Introduction: Oral anticoagulant is essential for the treatment and prevention of thromboembolism. Warfarin is an effective oral anticoagulant in prevention and treatment of thromboembolism. However, warfarin is frequently associated with adverse event (AE) requiring hospitalization. Method: We performed a retrospective cohort study of all patients admitted to a large tertiary public hospital for warfarin-related AEs. Patients were grouped based on bleeding severity and the direct medical cost was also calculated. Results: During the 4 years study period, a total of 224 patients were admitted for warfarin-related AEs. Mean age of patients admitted was 65.1 years (standard deviation [SD] = 11.5). More than half, 59.6%, of them were on warfarin for prevention of stroke in atrial fibrillation or atrial flutter. Major bleeding occurred among 50.9% of the patients with gastrointestinal bleed, 34 (29.8%), as the common site of bleed. Patients with major bleed had longer median hospital stay of 4 days (interquartile range [IQR] = 5) compared to 3 (IQR = 3) days in non-major bleed. There were 17 (14.9%) death among the major bleeders. Mean medical cost for managing warfarin-related AEs was USD 708.08. Conclusion: The admitted patients were equally distributed in terms of bleeding severity. Medical cost incurred for managing warfarin-related AEs increased with the severity of bleeding.