Introduction:Burnout is a widely known phenomenon. It is defined as a state of prolonged physical and psychological exhaustion and is experienced virtually by every medical student due to the highly demanding nature of medical education. This study probes into the prevalence and psychosocial determinants of burnout in Pakistani medical students.Methods:A descriptive, cross-sectional study design and convenience (non-probability) sampling technique were employed in undergraduate medical students from years 1-5. A total of 777 medical students from two medical colleges were included in the study from May-August, 2014. An English version of the Copenhagen Burnout Inventory (CBI) and a series of demographic questions, intermixed with questions from other topics, were included in the questionnaire. Data was analysed by using SPSS ver.21.Results:The majority of students were females and enrolled in the third year of MBBS. Of the medical students involved, 30.6% were found to have high/very high levels of burnout (Kristenson’s burnout scoring). Although 38.7% of students said that they did not feel burned out after reading the definition of burnout given in the questionnaire, 35.9% out of these students actually had high levels of burnout according to CBI. According to the multiple regression analysis, burnout in medical students was significantly associated with age, gender, doctor parents, no help or no supportive resources (e.g., from colleagues), lack of time off, lack of belief in what you do, fear of big consequences of failure, family responsibilities, and uncertain future. Perception of teachers lacking leadership skills and doing too much study with little balance was associated with low burnout scores.Conclusion:There is a high prevalence of burnout in Pakistani medical students. The present study identifies several factors associated with burnout in Pakistani medical students. Although these factors are a part of daily life of medical students, their identification should prompt the use of effective coping strategies and skills, thus, minimising their burnout levels.