In the study reported here, the authors test the hypothesis that internists completing residencies in a highly structured, problem-oriented residency program approach clinical problem-solving differently than do internists whose residencies were not problem-oriented. The vehicle for the study was the certifying examination of the American Board of Internal Medicine (ABIM) in 1978, 1979, and 1980. Performance on patient management problems (PMPs) and multiple-choice questions was analyzed for candidates for ABIM certification whose residency had been problem-oriented, for candidates whose residencies had been classified as nonproblem-oriented, and for the national pool of U.S. medical graduates. Internists trained in the problem-oriented residency program achieved significantly higher PMP scores than did the national pool in two of the three years and on true-false questions in one of the years. No differences were detected between the problem-oriented group and their nonproblem-oriented colleagues.