Background: During the last decade, academic life at the medical school of the Pontificia Universidad Católica de Chile has been thoroughly affected by a curricular reform process. Changes started in 1993 and have continued up until now. This reform did not have an experimental design to allow for a scientific evaluation of its effects. However, it seems interesting to study the evolution of indices of academic performance of our students during this period. Aim: To evaluate the academic performance of medical students between 1989 and 1999. Subjects and Methods: All undergraduate students enrolled between 1989 and 1999. Academic performance was evaluated by 1) failure to pass one or more courses, 2) delay to complete the third year of studies, 3) withdrawal from school and 4) medical school grades. Results: All indices of academic performance changed during the period of study. Failure to pass, delay and withdrawal from school significantly decreased, whereas medical school grades improved, particularly in basic and pre-clinical subjects. Conclusions: Academic performance of medical students improved consistently between 1989 and 1999. While specific causal relationships cannot be established, we believe that this improvement is likely related to the curricular reform. This reform included horizontal and vertical integration of academic contents, greater emphasis in problem-based learning and additional instances of evaluation such as the repetition exam (Rev Méd Chile 2002; 130: 437-445)