ObjectiveTo describe the use of pre- and postrotation testing to objectively measure student knowledge during an ambulatory care advanced pharmacy practice experience (APPE) that used interactive disease state discussions. MethodsStudents on an ambulatory care APPE with select faculty preceptors at a school of pharmacy completed a pretest at the beginning and posttest at the end of the rotation that focused on common disease states in an ambulatory setting. Students were not aware of when assessments would occur. Throughout the APPE, the students participated in disease state discussions and applied the information in patient care encounters during the APPE. The tests were used to assess the students' knowledge of key therapeutic concepts. ResultsStudent knowledge improved as measured by a significant improvement in posttest scores from pretest scores. However, a satisfactory score of 70% correct was not uniformly attained and, in analyzing specific questions, key concepts on the disease states were missed by students despite the overall improvement in test scores. ConclusionsDisease states discussions augmented an ambulatory care APPE and played a significant role in improving student knowledge on core disease concepts. Although a posttest was useful in assessing therapeutic information gained through an APPE, only 60% of students achieved a satisfactory level of performance. Incorporation of a formalized assessment at the end of an APPE as an objective means of determining minimum pharmacotherapy competency would be beneficial.