Findings of two independently conducted longitudinal studies conducted in follow-up to the development and implementation of pre-clinical cancer prevention courses at different medical schools are discussed. While required to meet common contract objectives, each program was designed and integrated relative to content and instructional methods to accommodate existing curricular patterns (one traditional, the other systems-oriented). In each study, measures were employed at specified intervals in students' pre-clinical and clinical programs to assess and report knowledge gain (loss), changing perceptions and attitudes toward disease, and changing behaviors and interest relative to disease intervention. Results show that the prevention courses offered had a positive impact on student knowledge and attitude and little impact on clinical behavior. Because of the positive correlations found between knowledge and attitudes in both studies, it is suggested that continued development of prevention education programs, particularly with formal expansion and reinforcement in clinical programs, could likely have beneficial results in the future. (JN)