Surgical excision is the treatment of choice for stage II, III and resectable stage IV melanoma and is curative in most cases. Given the recent success of immunotherapy for the treatment of patients with advanced metastatic melanoma, the use of immunotherapy has been evaluated in the adjuvant setting for patients at high risk of recurrence. In this context, Nivolumab prolonged Recurrence-Free Survival (RFS) while reducing toxicity compared with Ipilimumab in a phase III clinical trial, and was subsequently FDA-approved in December 2017 for adjuvant treatment of locally advanced melanoma with metastatic lymph node involvement after resection of cutaneous lesions. While a fraction of patients benefit from adjuvant PD-1 immunotherapy, approximately 40% of patients are still relapsing despite this adjuvant treatment, without being able to identify them early and with poor understanding of resistance mechanisms. Additionally, about 15% of the patients will develop serious adverse effects driven by immunotherapy and often discontinuing or even contraindicating the onset of subsequent treatments, hence affecting global patients care. It is therefore of prime importance to identify clinical features able to predict response and toxicities to adjuvant immunotherapy in melanoma.