CACI No. 518. Medical Malpractice: Res ipsa loquitur
Judicial Council of California Civil Jury Instructions (2024 edition)
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518.Medical Malpractice: Res ipsa loquitur
[Name of plaintiff] may prove that [name of defendant]’s negligence caused
[his/her/nonbinary pronoun] harm if [he/she/nonbinary pronoun] proves all
of the following:
1. That [name of plaintiff]’s harm ordinarily would not have
occurred unless someone was negligent; [In deciding this issue,
you must consider [only] the testimony of the expert witnesses.]
2. That the harm occurred while [name of plaintiff] was under the
care and control of [name of defendant]; and
3. That [name of plaintiff]’s voluntary actions did not cause or
contribute to the event[s] that harmed [him/her/nonbinary
pronoun].
If you decide that [name of plaintiff] did not prove one or more of these
three things, then you must decide whether [name of defendant] was
negligent in light of the other instructions I have read.
If you decide that [name of plaintiff] proved all of these three things, you
may, but are not required to, find that [name of defendant] was negligent
or that [name of defendant]’s negligence was a substantial factor in
causing [name of plaintiff]’s harm, or both.
[Name of defendant] contends that [he/she/nonbinary pronoun/it] was not
negligent or that [his/her/nonbinary pronoun/its] negligence, if any, did not
cause [name of plaintiff] harm. If after weighing all of the evidence you
believe that it is more probable than not that [name of defendant] was
negligent and that [his/her/nonbinary pronoun/its] negligence was a
substantial factor in causing [name of plaintiff]’s harm, you must decide
in favor of [name of plaintiff]. Otherwise, you must decide in favor of
[name of defendant].
New September 2003; Revised December 2011
Directions for Use
The first paragraph of this instruction sets forth the three elements of res ipsa
loquitur. The bracketed sentence in element 1 should be read only if expert
testimony is introduced. The word “only” within that sentence is to be used if the
court has determined that the issue of the defendant’s negligence involves matters
beyond common knowledge.
The second paragraph explains that if the plaintiff fails to establish res ipsa loquitur
as a presumption, the jury may still find for the plaintiff if it finds based on its
consideration of all of the evidence that the defendant was negligent. (See Howe v.
472
Seven Forty Two Co., Inc. (2010) 189 Cal.App.4th 1155, 1163-1164 [117
Cal.Rptr.3d 126].)
If the plaintiff has established the three conditions that give rise to the doctrine, the
jury is required to find that the accident resulted from the defendant’s negligence
unless the defendant comes forward with evidence that would support a contrary
finding. (See Cal. Law Revision Com. comment to Evid. Code, § 646.) The last two
paragraphs of the instruction assume that the defendant has presented evidence that
would support a finding that the defendant was not negligent or that any negligence
on the defendant’s part was not a proximate cause of the accident. In this case, the
presumption drops out, and the plaintiff must then prove the elements of negligence
without the benefit of the presumption of res ipsa loquitur. (See Howe,supra, 189
Cal.App.4th at pp. 1163-1164; see also Evid. Code, § 646(c).)
Sources and Authority
• Res ipsa loquitur. Evidence Code section 646(c).
• Presumption Affecting Burden of Producing Evidence. Evidence Code section
604.
• “In California, the doctrine of res ipsa loquitur is defined by statute as ‘a
presumption affecting the burden of producing evidence.’ The presumption arises
when the evidence satisfies three conditions: ‘ “(1) the accident must be of a
kind which ordinarily does not occur in the absence of someone’s negligence;
(2) it must be caused by an agency or instrumentality within the exclusive
control of the defendant; (3) it must not have been due to any voluntary action
or contribution on the part of the plaintiff.” ’ A presumption affecting the burden
of producing evidence ‘require[s] the trier of fact to assume the existence of the
presumed fact’ unless the defendant introduces evidence to the contrary. The
presumed fact, in this context, is that ‘a proximate cause of the occurrence was
some negligent conduct on the part of the defendant. . . .’ If the defendant
introduces ‘evidence which would support a finding that he was not negligent or
that any negligence on his part was not a proximate cause of the occurrence,’ the
trier of fact determines whether defendant was negligent without regard to the
presumption, simply by weighing the evidence.” (Brown v. Poway Unified School
Dist. (1993) 4 Cal.4th 820, 825-826 [15 Cal.Rptr.2d 679, 843 P.2d 624], internal
citations omitted.)
• “ ‘The doctrine of res ipsa loquitur is applicable where the accident is of such a
nature that it can be said, in the light of past experience, that it probably was the
result of negligence by someone and that the defendant is probably the one
responsible.’ ” (Howe,supra, 189 Cal.App.4th at p. 1161.)
• “Res ipsa loquitur is an evidentiary rule for ‘determining whether circumstantial
evidence of negligence is sufficient.’ ” (Howe,supra, 189 Cal.App.4th at p.
1161, internal citation omitted.)
• The doctrine “is based on a theory of ‘probability’ where there is no direct
evidence of defendant’s conduct, permitting a common sense inference of
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negligence from the happening of the accident.” (Gicking v. Kimberlin (1985)
170 Cal.App.3d 73, 75 [215 Cal.Rptr. 834].)
• “All of the cases hold, in effect, that it must appear, either as a matter of
common experience or from evidence in the case, that the accident is of a type
which probably would not happen unless someone was negligent.” (Zentz v.
Coca Cola Bottling Co. of Fresno (1952) 39 Cal.2d 436, 442-443 [247 P.2d
344].)
• “In determining the applicability of res ipsa loquitur, courts have relied on both
expert testimony and common knowledge. The standard of care in a professional
negligence case can be proved only by expert testimony unless the conduct
required by the particular circumstances is within the common knowledge of the
layperson.” (Blackwell v. Hurst (1996) 46 Cal.App.4th 939, 943 [54 Cal.Rptr.2d
209], internal citations omitted.)
• “Under the doctrine of res ipsa loquitur and this common knowledge exception,
it is proper to instruct the jury that it can infer negligence from the happening of
the accident itself, if it finds based on common knowledge, the testimony of
physicians called as expert witnesses, and all the circumstances, that the injury
was more likely than not the result of negligence.” (Gannon v. Elliot (1993) 19
Cal.App.4th 1, 6 [23 Cal.Rptr.2d 86], internal citation omitted.)
• “The fact that a particular injury rarely occurs does not in itself justify an
inference of negligence unless some other evidence indicates negligence. To
justify res ipsa loquitur instructions, appellant must have produced sufficient
evidence to permit the jury to make the necessary decision. He must have
presented ‘some substantial evidence which, if believed by the jury, would
entitle it to draw an inference of negligence from the happening of the accident
itself.’ ” (Blackwell, supra, 46 Cal.App.4th at p. 944, internal citations omitted.)
• The purpose of the second “control” requirement is to “link the defendant with
the probability, already established, that the accident was negligently caused.”
(Newing v. Cheatham (1975) 15 Cal.3d 351, 362 [124 Cal.Rptr. 193, 540 P.2d
33].) The control requirement is not absolute. (Zentz, supra, 39 Cal.2d at p. 443.)
• “The purpose of [the third] requirement, like that of control by the defendant is
to establish that the defendant is the one probably responsible for the accident.
The plaintiff need not show that he was entirely inactive at the time of the
accident in order to satisfy this requirement, so long as the evidence is such as
to eliminate his conduct as a factor contributing to the occurrence.” (Newing,
supra, 15 Cal.3d at p. 363, internal citations omitted.)
• The third condition “should not be confused with the problem of contributory
negligence, as to which defendant has the burden of proof. . . . [I]ts purpose,
like that of control by the defendant, is merely to assist the court in determining
whether it is more probable than not that the defendant was responsible for the
accident.” (Zentz, supra, 39 Cal.2d at p. 444.)
• “[Evidence Code section 646] . . . classified the doctrine as a presumption
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affecting the burden of producing evidence. Under that classification, when the
predicate facts are established to give rise to the presumption, the burden of
producing evidence to rebut it shifts to the defendant to prove lack of negligence
or lack of proximate cause that the injury claimed was the result of that
negligence. As a presumption affecting the burden of producing evidence (as
distinguished from a presumption affecting the burden of proof), if evidence is
presented to rebut the presumed fact, the presumption is out of the case - it
‘disappears.’ But if no such evidence is submitted, the trier of fact must find the
presumed fact to be established.” (Howe,supra, 189 Cal.App.4th at p. 1162.)
• “ ‘If evidence is produced that would support a finding that the defendant was
not negligent or that any negligence on his part was not a proximate cause of the
accident, the presumptive effect of the doctrine vanishes.’ ‘[T]he mere
introduction of evidence sufficient to sustain a finding of the nonexistence of the
presumed fact causes the presumption, as a matter of law, to disappear.’ When
the presumptive effect vanishes, it is the plaintiff’s burden to introduce actual
evidence that would show that the defendant is negligent and that such
negligence was the proximate cause of the accident.” (Howe,supra, 189
Cal.App.4th at p. 1163, internal citations omitted.)
• “As the [Law Revision Commission] Comment [to Evidence Code section 646]
explains, even though the presumptive effect of the doctrine vanishes, ‘the jury
may still be able to draw an inference that the accident was caused by the
defendant’s lack of due care from the facts that gave rise to the
presumption. . . . [¶] . . . [¶] . . . An inference of negligence may well be
warranted from all of the evidence in the case even though the plaintiff fails to
establish all the elements of res ipsa loquitur. In appropriate cases, therefore, the
jury may be instructed that, even though it does not find that the facts giving rise
to the presumption have been proved by a preponderance of the evidence, it may
nevertheless find the defendant negligent if it concludes from a consideration of
all the evidence that it is more probable than not that the defendant was
negligent.’ ” (Howe,supra, 189 Cal.App.4th at p. 1163, internal citation
omitted.)
• “It follows that where part of the facts basic to the application of the doctrine of
res ipsa loquitur is established as a matter of law but that others are not, the
court should instruct that application of the doctrine by the jury depends only
upon the existence of the basic facts not conclusively established.” (Rimmele v.
Northridge Hosp. Foundation (1975) 46 Cal.App.3d 123, 130 [120 Cal.Rptr.
39].)
Secondary Sources
1 Witkin, California Evidence (5th ed. 2012) Burden of Proof and Presumptions,
§§ 116-120
3 Levy et al., California Torts, Ch. 31, Liability of Physicians and Other Medical
Practitioners, § 31.32 (Matthew Bender)
36 California Forms of Pleading and Practice, Ch. 415, Physicians: Medical
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Malpractice, § 415.11[2] (Matthew Bender)
17 California Points and Authorities, Ch. 175, Physicians and Surgeons, § 175.50
(Matthew Bender)
519-530. Reserved for Future Use
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© Judicial Council of California.
