Medical education is highly demanding, with students facing intense academic, emotional, and professional challenges. First-year students face the pressures of adjusting to a rigorous curriculum and new social environments, while final-year students experience heightened stress related to career uncertainty and impending clinical responsibilities. Understanding the sources of stress and coping strategies at different stages of training is crucial for developing targeted interventions that promote student well-being and academic success. Hence, this study aimed to assess the differences in perceived stress sources and coping strategies among first and final-year undergraduate medical students using an online survey. Sociodemographic information was collected, and stress levels were measured using the Perceived Stress Scale, while sources of stress were identified with the Medical Student Stressor Questionnaire. Coping strategies were evaluated using the Brief-COPE. Statistical analysis was performed using SPSS, with Chi-square tests to compare groups. A total of 264 medical students (132 first-year, 132 final-year) participated in the study. First-year students reported higher levels of stress, with 84.8% experiencing moderate stress, while final-year students showed more balanced stress distribution. Academic, interpersonal, and teaching-related stressors were most significant. First-year students predominantly used problem-focused coping, whereas final-year students employed more emotion-focused and avoidant coping strategies, with significant differences observed between the cohorts. Our results highlight the evolving stress experiences and coping strategies across the medical curriculum, underscoring the need for targeted mental health support that promote student well-being.