This review provides an overview of clinical manifestations, diagnostic approaches, and management strategies for cardiotoxicities associated with the use of immune checkpoint inhibitors (ICI). ICI therapy represents a novel treatment modality for advanced-stage malignancies, including melanoma, metastatic renal cell cancer, and non-small cell lung cancers. ICIs have been shown to provide significant mortality benefit and are generally well-tolerated. The major adverse effects associated with ICIs are immune-mediated toxicities, which can affect multiple different organ systems. Immune-mediated cardiotoxicity is quickly gaining recognition as a rare but devastating consequence of ICI therapy. ICI-associated cardiotoxicity can manifest in a variety of ways, including fulminant lymphocytic myocarditis, supraventricular and ventricular arrhythmias, pericardial disease, and even Takotsubo-like cardiomyopathy. While not entirely clear, the primary mechanism of injury has been hypothesized to involve hyperactivation and infiltration of cytotoxic T-cells into cardiovascular tissue. The diagnosis is typically made using cardiac biomarkers and imaging, in conjunction with endomyocardial biopsy when necessary. Treatment options remain limited and generally focus on immunosuppression.