”Habit” is a time-honored component of the law of evidence. Habit evidence is generally understood as specific conduct which occurs repetitively, over a period of time, in response to a known stimulus. Habitual conduct is also thought to be non-volitional, suggesting that it encompasses conduct without thought.

This paper focuses on whether the practice of medicine is, in any respect, “habitual.” Are medical negligence litigants, plaintiffs and physicians, entitled to introduce evidence of physician habit to demonstrate deviation from or compliance with the applicable standard of care? Is the practice of medicine entirely volitional and judgmental, such that classic habit evidence is inapplicable to medical negligence litigation? This Article addresses these topics in an effort to identify the various positions adopted by courts in the United States and recommends that courts receive physician habit evidence in medical negligence trials.