Faculty from six eastern health science schools, from Florida to Nova Scotia, developed a new series of group-learning units during 1983 and 1984 using a recently developed patient-oriented problem-solving approach. The purpose of the units was to teach problem solving by applying the concepts and principles of pharmacology to therapeutic problems, and to find ways to engage students actively in their learning of this material. The development team envisioned that these goals would be met by means of well-crafted teaching units that could be evaluated and, if acceptable, used by academic pharmacologists in their teaching. The units were developed, edited, reviewed by experts, and field-tested with students at the authors' schools; editing and publication were done by the study's sponsor, the Upjohn Company. The results of the field trials (which indicated no need for revisions of the units) showed that the units were well crafted and that the students had higher scores on tests of their knowledge of pharmacology after they had used the units.