Immunotherapy, encompassing immune checkpoint inhibitors, antibody therapy, and chimeric antigen receptor (CAR)-T-cell therapy, has emerged as a groundbreaking approach by harnessing the immune system to selectively target and eliminate malignant cells. However, its widespread application has revealed a spectrum of severe, life-threatening hemostatic abnormalities, including immune thrombocytopenia, Evans syndrome, thrombotic thrombocytopenic purpura, acquired haemophilia A, thrombosis, disseminated intravascular coagulation and CAR-T-associated coagulopathy. These disorders may arise from excessive immune activation, autoantibody production, and intricate crosstalk between inflammatory pathways and coagulation cascades. Despite increasing recognition, their pathophysiological mechanisms remain incompletely understood, and standardized management strategies have yet to be established, posing significant clinical challenges. Given the safety concerns surrounding immunotherapy, timely diagnosis and appropriate intervention of these abnormalities are crucial. This review provides a comprehensive overview of the epidemiology, distinct clinical manifestations, emerging pathophysiological insights, and evolving treatment paradigms of immunotherapy-associated hemostatic abnormalities to enhance clinicians' understanding and guide therapeutic decision-making.