The authors' threefold purpose in this article was to (a) propose a model of the relationship between the emotional aspects of physicians' attitudes to medical errors (e.g., fear of litigation) and their functional consequences (e.g., tendency to defensive practice); (b) develop a measure of some of these attitudes; and (c) provide empirical support for some of the relationships in the model. Medical students and physicians responded to a questionnaire concerning their attitudes toward uncertainty and medical error. The dependent variables were two dimensions of attitudes to uncertainty ("reluctance to disclose uncertainty" and "stress from uncertainty") and four dimensions of attitudes to medical error ("fear of litigation," "support for self-regulation," "tendency to defensive practice," and "self-disclosure of errors"). Stress from uncertainty correlated with fear of malpractice litigation and defensive practice. They concluded that interventions that aim to increase physicians' tolerance of uncertainty may also reduce their fear of malpractice litigation and their tendency to defensive practice.