To evaluate the psychological well-being of medical students a relatively new self-report questionnaire (the depression, anxiety, and stress scale) was used alongside an established instrument (the beck depression and anxiety inventories) in a group of medical students. A total of 928 medical students (49.4% female; 50.6% male) participated voluntarily into this cross-sectional study. Students completed the Turkish versions of the depression anxiety stress scale (DASS), beck depression, and anxiety inventories together with a questionnaire about their socio-demographic characteristics. Mild and moderate levels of depression were found in 30.5% and severe and extremely severe levels of depression in 8.5% of students. Mild and moderate levels of anxiety and stress were present in 35.8% of the participants. Depression and anxiety were more frequently reported by female students. Depression was more frequent among first-year students, students in a poor economic situation and those who were not satisfied with their medical education. The frequency of depression and anxiety were seen to decrease with increasing grades. Bland and Altman plots showed an agreement between beck inventories and depression, anxiety, and stress scales, whereas the agreement between anxiety scales was found to be better than that of depression scales. Depression and anxiety are seen frequently among medical students in Turkey. The psychological distress was influenced only to a modest degree by traditional socio-demographic characteristics. Either the traditional beck inventories or the newer depression anxiety and stress scales can be used for non-clinical screening purposes in individuals.