The authors present a 10-year review of patients registered at the British Columbia Cancer Agency (BCCA) who underwent lymph node dissection for malignant melanoma. Pathological findings in the regional lymph nodes were correlated with primary site, growth pattern, depth of invasion and Clark's level. Elective lymph node dissection (ELND) was performed in 223 patients, and the overall positivity rate (pathologically involved nodes) was 16%. Survival rates for patients who had ELND were compared with those for BCCA patients not having had ELND and patients from the University of Sydney, Sydney, Australia. Although patients who underwent ELND had thicker and more frequently ulcerated primary tumours than patients with stage I disease who did not undergo ELND, survival was better in the group who had ELND. However, when all potential prognostic factors were analysed by multivariate analysis, ELND was not a significant factor in prognosis. Therapeutic lymph node dissection (TLND) was performed in 50 patients at the time the primary tumour was diagnosed, and involvement of the lymph nodes was found in 36. Of 525 patients with clinical stage I disease who did not have ELND, disease recurred in the regional lymph nodes in 119; 86 of them had TLND for recurrence (RTLND). Median survival rates from the time of diagnosis of the primary lesion for ELND-positive, TLND-positive and RTLND patients were 4.2, 2.7 and 4.4 years respectively; the differences were not significant. New treatments are required for patients with involved regional lymph nodes.