This study addressed three evaluation questions about the effectiveness of a workshop to teach residents how to teach: (1) How do residents evaluate their own teaching skills? (2) How do students evaluate residents' teaching skills? (3) Do residents of various specialties differ in their teaching skills? One hundred and five residents rated their skills on the Inventory of Teaching Behavior significantly higher after attending the workshop than before it. Third-year students evaluated the teaching skills of both residents who had attended the workshop and those who had not. On four of the nine items of the Clinical Teaching Assessment Form, students rated residents who had attended significantly higher than the control residents. Some differences in teaching skills among the various specialties were found as were differences between resident self-rating and student rating. These data suggest that giving residents instruction can improve their teaching skills. By doing so, both the residents and the programme can benefit.