This review focuses on the toxicities associated with cancer immunotherapies, particularly checkpoint inhibitors and chimeric antigen receptor (CAR) T cells. It discusses the pathophysiology, diagnosis, and management of these toxicities, which are distinct from those of other cancer therapies. The review highlights the unique mechanisms by which checkpoint inhibitors and CAR T cells operate, leading to specific toxicities such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and immune-related adverse events (irAEs). The incidence and severity of these toxicities vary depending on the type of immunotherapy and the patient's response. Management strategies, including the use of steroids and immunomodulating agents, are discussed, along with guidelines for monitoring and treatment. The review also covers specific toxicities such as dermatologic, gastrointestinal, hepatotoxic, endocrinopathic, thyroid, pituitary, pneumonitic, rheumatologic, neurologic, renal, and ocular toxicities, providing a comprehensive overview of the challenges and approaches in managing these complications.This review focuses on the toxicities associated with cancer immunotherapies, particularly checkpoint inhibitors and chimeric antigen receptor (CAR) T cells. It discusses the pathophysiology, diagnosis, and management of these toxicities, which are distinct from those of other cancer therapies. The review highlights the unique mechanisms by which checkpoint inhibitors and CAR T cells operate, leading to specific toxicities such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and immune-related adverse events (irAEs). The incidence and severity of these toxicities vary depending on the type of immunotherapy and the patient's response. Management strategies, including the use of steroids and immunomodulating agents, are discussed, along with guidelines for monitoring and treatment. The review also covers specific toxicities such as dermatologic, gastrointestinal, hepatotoxic, endocrinopathic, thyroid, pituitary, pneumonitic, rheumatologic, neurologic, renal, and ocular toxicities, providing a comprehensive overview of the challenges and approaches in managing these complications.