A randomized controlled time series design was used to evaluate the influence of an educational intervention designed to improve the presentation skills of family medicine residents. Each resident gave three presentations, with the educational intervention occurring between the first and second presentations in the experimental group, and between the second and third presentations in the control group. The presentations were evaluated using a standardized format. The experimental group, in contrast to the control group, showed significant improvement in scores for all major criteria after receiving the educational intervention between presentations 1 and 2. This improvement continued with repetition between presentations 2 and 3. After receiving the educational intervention between presentations 2 and 3, the control group also demonstrated significant improvement in several key areas. We conclude that an educational intervention can improve the presentation skills of family medicine residents. Education coupled with repeated opportunities for presentation will produce a greater improvement in resident performance than repeated presentations alone.