Medical students need to be taught explicitly about decision making to be prepared for the changing health care environment. Medical decision making curricula have received favourable responses from students and have influenced some aspects of student performance. Questions remain about the impact of the teaching on students' general problem solving skills. A 15 hour course covering decision making topics was presented during a preclinical elective preceptorship for 5 years. Problem solving ratings made by clinical supervisors for the third year psychiatry and internal medicine clerkships were not better for the students who had the instruction and clinical experience than for the students in the comparison group. The results suggest that this approach to teaching decision making requires further development and testing.