The authors examined the role of systemic adjuvant therapy in patients with high-risk, resected, primary melanoma. Outcomes of interest included overall survival, disease-free survival, adverse effects, and quality of life. A systematic review of the literature was conducted to locate randomized controlled trials, practice guidelines, meta-analyses, and reviews published between 1980 and 2004.Thirty-seven randomized controlled trials, 2 meta-analyses, and 1 systematic review were identified that investigated interferon, levamisole, vaccine, or chemotherapy as adjuvant therapy. For high-dose interferon-␣, the results from 3 randomized trials conducted by the Eastern Cooperative Oncology Group were pooled, and a metaanalysis of 2-year death rates yielded a risk ratio of 0.85 (95% confidence interval, 0.73-0.99; P ϭ .03). Five randomized trials comparing lowdose interferon-␣ with observation only after surgery did not detect a statistically significant improvement in overall survival. A metaanalysis of 4 levamisole trials did not demonstrate a significant survival benefit for levamisole over control; similarly, no survival benefit was demonstrated by data from randomized controlled trials with vaccines (9 trials) or with chemotherapy (10 trials). In this review of the available literature, no systemic adjuvant therapy was identified that conferred a significant overall survival benefit in patients with high-risk, resected, primary melanoma. However, high-dose interferon should be considered in the treatment of these patients, because such therapy is associated with a significant improvement in disease-free survival and a reduction in 2-year mortality. Until the results of ongoing trials are available, the authors could not state with confidence whether such therapy benefits patients with microscopically detected, sentinel lymph node-positive disease.