This study examined the trends in the medical knowledge of osteopathic internal medicine residents in American Osteopathic Association-approved residency programs during a recent lO-year period and compared these trends with the declining medical knowledge observed for internal medicine residents graduated from allopathic medical schools and trained in allopathic residency programs. These results demonstrate a similar pattern of declining medical knowledge that appears to have leveled off during the past few years of the study. These trends occurred among candidates from both large and smaller training institutions. Various factors may have contributed to these observations.