The Sunbelt Melanoma Trial, a multicenter, prospective randomized clinical study, evaluated the role of high-dose interferon alfa-2b (HDI) therapy for patients with a single positive sentinel lymph node (SLN) metastasis treated with a completion lymph node dissection (CLND). A second protocol in the trial evaluated the prognostic significance of using molecular markers to identify submicroscopic metastases in sentinel lymph nodes that were negative by routine pathologic analysis. The role of CLND with or without adjuvant HDI was evaluated in this group of patients. The results of the study demonstrated that adjuvant HDI offered no survival benefit for patients with a single positive SLN in terms of disease-free or overall survival. Molecular staging using polymerase chain reaction (PCR) for melanoma markers did not identify a high-risk group of patients at increased risk of melanoma recurrence. Additional treatment of these patients who were PCR-positive with either CLND alone or CLND plus HDI did not improve their survival. Additional studies from the Sunbelt Melanoma Trial helped to validate the operational standards of the SLN biopsy procedure and defined the complication rates for both SLN biopsy and CLND. A prognostic risk calculator has been developed from trial data, and the importance of different micrometastatic tumor burden measurements was reported. Although the Sunbelt Melanoma Trial did not demonstrate an improvement in survival with HDI, it is an important trial that highlights the significance of surgeon-initiated randomized clinical trials that incorporate surgical techniques, molecular biomarkers, and adjuvant therapy.