Sentinel node biopsy has become an integral part of the management of malignant melanoma. Here, the authors describe the technique that is used at the St George's Hospital Melanoma Unit. Results obtained over the past 5 years on a cohort of patients are presented. Three hundred and forty seven patients were entered in the study. Population demographics were analysed for both the primary melanoma and for sentinel node positive status. Histological features of the primary, particularly regression were noted and, in addition to metastatic disease, the presence of capsular naevus cells within the node also recorded. Complications associated with the procedure have been presented along with the specificity and sensitivity of the technique. The relative influence of both Breslow thickness and sentinel node positivity were analysed statistically and Kaplan-Meier survival curves produced for the cohort as a whole. This confirmed the accuracy of sentinel node biopsy and its role as a prognostic indicator.