Background: Sleep is crucial for brain growth and function, it plays a significant role in human life and health. The present study was conducted to evaluate sleep quality in undergraduate medical students. Methods: 470 MBBS students of both genders were given a pre-designed pre-tested semi structured self- administered questionnaire. They were divided into 3 groups. Group I were interns, group II were third and final year and group III were second and first year. Socio-demographic data, dietary habits and physical activity was recorded. Pittsburgh sleep quality index (PSQI) was used to assess the quality of sleep. Results: Group I were interns, group II were third and final year and group III were second and first year. Group I had 30 males and 50 females, group II had 85 males and 105 females and group III had 92 males and 108 females. Sleep quality was very good in 31% in group I, 25% in group II and 27% in group III. It was fairly good in 49% in group I, 36% in group II and 50% in group III. It was fairly bad in 15% in group I, 20% in group II and 16% in group III. It was fairly bad in 5% in group I, 19% in group II and 7% in group III. Sleep latency <15 minutes was seen in 41.2% in group I, 23% in group II and 40.4% in group III. The difference was significant (P< 0.05).The mean subjective sleep quality score was 0.91, sleep latency was 1.3, sleep duration was 1.1, habitual sleep efficiency was 1.0, sleep disturbances was 1.4, use of sleeping medications was 0.27, daytime dysfunction was 0.82. Global PSQI score (total score) was 6.8. Sleep was good in 47% and poor in 53% medical students. The difference was non- significant (P> 0.05). Conclusion: The most of medical students had poor sleep quality. More focus is needed to determine the variables influencing medical students' sleep quality and to develop potential ways to avoid any long-term effects in order to improve their quality of sleep.