Medical mistakes often are responsible for patient injury and suffering, but not all such mistakes are negligent. In the United States, injured patients have recourse to legal action under the common law. The medical malpractice tort trial system is intended to provide compensation for patients who have been negligently injured and to deter future negligent acts by physicians. The deterrent function of torts largely rests on practitioners' capacity and willingness to internalize, or 'process', the lessons of tort trials. However, physicians' willingness or ability to process the tort deterrent signal, while widely assumed in much contemporary legal writing on medical malpractice, has never been empirically verified. This study is a qualitative assessment of how practicing physicians process the tort deterrent signal. We interviewed a random sample of 47 internists, surgeons, and obstetrician/gynecologists from New York State as part of the Harvard Medical Practice Study. The interviews reveal three notable findings: physicians in our sample largely define medical negligence by reference to moral qualities of the practitioner; they claim that lawyers and the legal process of tort trials lack the moral authority to guide medical practice; and finally, while they consequently reject the lessons of lawyer-dominated, confrontational tort trials, they indicate that they would respond more favorably to hospital-based, physician-led, educational quality-control measures. Based on these findings, we identify several potential impediments to the receipt and processing of the tort deterrent signal by individual physicians and we suggest that the interview results support the notion of institutional liability for medical malpractice.