Introduction: Sleep is the time of the day when the mind and body finally get the well-deserved rest. Medical students, are constantly compromising on their sleep, in order to spare time for increased workload, curricular demands, social expectations, technology for recreation and communication. Medical students are also subjected to potential stressful situations like social responsibility, an overwhelming academic curriculum and having to learn complex clinical skills. Objectives: 1) To study the sleep pattern among undergraduate medical students. 2) To find the prevalence of perceived stress in study participants. 3)To determine the association of sleep pattern with perceived stress in study participants. Design: Cross-Sectional study. Methods: Total 350 undergraduate students from Vardhman Mahavir Medical College, Delhi were enrolled by stratified simple random sampling. A self-designed, pretested, semi structured questionnaire along with PSQI and PSS10 was used. Results: Out of 350 students, 41.7% (146) were females and 58.3% (204) were males. The mean age of the students was 20.22 ±1.63 years. About 57% (199) students had poor sleep quality and 67.7% (237) had moderate stress. Sleep Quality in study participants was significantly associated with Perceived Stress. Conclusion: This study reports high prevalence of poor sleep and perceived stress among medical undergraduate students.