The teaching of pharmacoepidemiology has been largely confined to health care professionals and graduate students. This paper reports an attempt to use problem-based learning (PBL) to teach the elements of that discipline to undergraduate science students. Carefully sequenced problems led students to consider the following issues: the terms used in epidemiology, merits and demerits of different epidemiological study designs, pharmacovigilance, the nature of evidence in law and science, economic evaluation of drugs and the use of drugs in different cultures. The 12-week course was taken by students in their final term prior to graduation. Multiple evaluation procedures were used: specific forms for assessing tutorial participation, individual explorations assessed usually by written essays and problem-solving exercises. The course has received high ratings from the students. The observations over a 10-year period suggest that PBL is a feasible approach to teach the social dimensions of drug use.