Leaders in preventive medicine and medical education have called for more attention to preventive medicine in medical education curricula. This study describes the implementation of a training program designed to introduce preventive medicine skills into the medical school curriculum. The specific issue addressed was smoking cessation. A two-hour workshop on the patient-centered approach to smoking intervention was presented to medical students during the family medicine rotation of the second-year clinical medicine course sequence. Two of the four student groups in the family medicine clinical rotation received the training and were afforded practice opportunity with at least one smoking patient at the clinical site. The other two groups went through the usual rotation with no special instruction or clinical emphasis on preventive interventions. Second-year medical students expressed positive perceptions of preventive medicine as assessed by self-rating on attributes important to successful preventive practice. These positive perceptions were retained by both groups after the clinical experience. Students with the workshop training were more confident in their smoking intervention skills and performed better overall on an objective clinical evaluation of intervention skills.