Background: Medical colleges are recognized as stressful environments that exert negative effects on the mental health of students. Mental illnesses decrease the performance of students in their profession. Depression among medical students is an area of increasing concern worldwide. This study aims to assess the prevalence of depressive symptoms and their causes among medical students. Method: A cross-sectional study was conducted on students of medical school in Peshawar, using a non-probability convenient sampling technique. A questionnaire consisting of socio-demographic variables and causes of depressive symptoms was used for data collection. The Hamilton Scale for Depression was used to assess the level of depression in students. Data obtained were collected and statistically analysed using SPSS Version 20 for Windows. Results: A total of 220 students participated in the study, with equal representation from each class. The overall prevalence of depressive symptoms was found to be 60.5%. Among these, 26.8% had mild depressive symptoms, 11.4% had moderate depressive symptoms, and 22.3% had severe depressive symptoms. The prevalence of depressive symptoms was relatively higher among 4th-year medical students. The study showed that depressive symptoms were more prevalent in males (61.8%) than in females (58.1%). Childhood trauma, drug abuse, broken relationships, financial problems, and academic stress were identified as major causes of depressive symptoms. Conclusion: A large number of medical students are suffering from depressive symptoms associated with avoidable and manageable causes. Hence, there is a need for early screening and proper counselling of the subjects.