Melanoma adjuvant therapy has substantially improved recurrence-free and distant metastasis-free survival in patients with resected high-risk disease, and more recently these advances have extended to earlier stages. However, important unmet needs remain, including the management of stage IIIA disease, the optimal treatment strategy after relapse on adjuvant therapy, and the identification of biomarkers capable of refining patient selection. This review summarizes recent advances and unresolved questions in the adjuvant and neoadjuvant treatment of melanoma. We discuss novel systemic strategies, including immune checkpoint inhibitor combinations and personalized neoantigen mRNA vaccines, together with the expanding role of neoadjuvant approaches. We also examine prognostic and predictive tools - such as clinicopathologic models, circulating tumor DNA, serum biomarkers, tumor microenvironment features, and gene expression profiling – that may help better define recurrence risk and therapeutic benefit. Current evidence suggests that although modern therapies have changed the natural history of resected melanoma, a substantial proportion of patients are still overtreated or undertreated when treatment decisions are based on stage alone. Future progress will depend on integrating biological risk stratification with clinical staging and on optimizing treatment sequencing across adjuvant and neoadjuvant settings.