Using data from 1,805 interns, residents, and fellows in Ontario, Canada, the authors report the prevalence of symptoms measured by the Center for Epidemiologic Studies Depression Scale (CES-D). They found that the proportion of subjects scoring as depressed was somewhat higher than that found in community studies. Women had higher depression scores than men. The proportion of unmarried house staff with moderate or severe depression scores was higher than that of married house staff. Considerable differences were found by specialty, and depression was most prevalent in the first year of postgraduate training. These findings have implications for those who direct postgraduate medical training or who seek to alleviate unnecessary stress in the postgraduate education experience.