Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that work by blocking CTLA-4, PD-1 or PD-L1 molecules. They help activate the immune system to recognize and eliminate cancer cells. Immune checkpoint inhibitors are monoclonal antibodies that actives the immune system against tumor cells, by blocking CTLA-4, PD-1, or PD-L1. Although they represent a breakthrough in immuno-oncology and have significant therapeutic benefits, their use is associated with the risk of immune-related adverse events (IRAEs). These result from an abnormal immune system response to healthy tissues, and one of their most serious consequences is cardiotoxicity. Adverse cardiovascular events such as atherosclerosis, myocarditis and cardiomyopathy carry high mortality and morbidity. Importantly, the mechanisms underlying ICIs-induced cardiotoxicity are not yet fully understood. Although their incidence is sometimes underestimated and downplayed, an increasing number of them are reported, The development of cardioimmuno-oncology, a new interdisciplinary field, is crucial for more effective monitoring and prevention of the cardiotoxic effects of ICIs therapy. In this literature review, we discuss the mechanism of action of immune checkpoint inhibitors and their associated cardiovascular events. Understanding the background of the pathomechanism of ICIs can be a helpful tool in discovering new strategies to prevent and treat cardiotoxicity.