Background: Sleep problems are common among young adults, especially university students who experience great psychological pressure due to the changes in career market and increased unemployment.Objectives: The aim of the study was to examine sleep habits and sleep problems of university students and to compare sleep of medical students to that of students of other faculties.Methods: A cross-sectional survey was conducted in Aristotle University of Thessaloniki. Students from different academic levels and faculties completed self-report, anonymous questionnaires.Results:A total of 309 students (47% males) from different faculties (33.5% medicine) were recruited (20.5 ±2 years).Reported mean duration of night sleep during weekdays was 6.6±1.4h, but during weekends 8.6± 1.9 (p<0.001). During the examinations period sleep duration was 6.4±1.7h. Only 39 (13%) students were working and 16 (41%) of them had a night shift. 18% were smokers, 76.4% drunk coffee to 'wake them up when sleepy' (1.3±1.2 cups) and 28 (9.1%) consumed alcohol to help them sleep when they had problems. 84% considered their sleep quality adequate, but 76.3% reported daytime sleepiness and 94% that their sleep duration was inadequate. Thinking of economic problems and economic crisis caused problems in the sleep of 11%. Snoring was reported in 21% (66.1% males) and sleeptalking in 23.6%.Sleep duration was shorter in medical students compared to other students in weekdays(5.7±0.9 vs 7.1±1.4, p<0.001) and during examinations (5.9±1.6 vs. 6.7±1.7, p=0.001).Conclusions: Among university students sleep duration is short especially in medical students and the majority believes that more sleep would be necessary.