PURPOSE: To compare the levels of achievement on the Medical Council of Canada (MCC) Qualifying Examination Part I of students in conventional and problem-based learning (PBL) curricula. METHOD: Students in three classes (1995, 1996, and 1997) took the MCC Qualifying Examination Part I upon completing their MD degrees. This examination tests core knowledge in the major disciplines and clinical reasoning skills. Candidates' scores were masked to protect confidentiality. Total scores, individual discipline scores, and pass/fail proportions were compared among the classes. RESULTS: The PBL classes of 1996 and 1997 performed better on the psychiatry component than did the 1995 conventional class (p = .001); the 1997 class also exceeded the 1995 and 1996 classes in preventive medicine and community health scores (p = .001). No difference emerged in other disciplines, clinical reasoning scores, total multiple-choice question scores, or the proportions of successful candidates. CONCLUSION: PBL and conventional curriculum graduates performed similarly, except in psychiatry and preventive medicine and community health, where PBL graduates scored higher.