This study investigated the influence of positive affect, induced by report of success on an anagram task, on medical decision making among third-year medical students. The subjects were asked to decide which one of six hypothetical patients, each of whom had a solitary pulmonary nodule, was most likely to have lung cancer. They were asked to verbalize their clinical reasoning as they solved the problem. The positive-affect and control groups did not differ in the tendency to make a correct choice, but subjects in the positive-affect condition were significantly earlier in identifying their choices. These subjects were also significantly more likely to go beyond the assigned task, expressing interesting in the cases of the other patients and trying to think about their diagnosis, even though that task was not assigned. The positive-affect subjects also showed evidence of configural or integrative consideration of the material to a reliably greater extent than did control subjects, and there was significantly less evidence of confusion or disorganization in their protocols than in those of controls. These findings are compatible with earlier work suggesting a different organizational process and greater efficiency in decision making among people in whom positive affect had been induced, and with recent work suggesting that positive affect facilitates flexibility and integration in problem solving. They also indicate that these effects may apply to the problem-solving strategies of professionals in clinical problem-solving situations.