Immune checkpoint inhibitors have radically changed oncology by significantly improving prognosis and survival of many patients, even at an advanced or metastatic stage. Some patients undergoing immunotherapy develop adverse immune-related events, presenting a toxicity spectrum that can affect any organ, separately or simultaneously, with different intensities depending on the treatment used and patient characteristics. We hereby suggest a diagnostic and therapeutic approach that any internist, general practitioner or emergency doctor should have facing digestive, cardiac and pulmonary toxicities.