In order to determine the value of the pelvic part of the radical dissection of the groin, the histories of 23 patients with Stage II (UICC) melanoma with histologically proved metastases of the iliac or obturator lymph nodes, or both, were studied. Histologically proved primary melanomas were found in 19 patients, 18 were localized on the leg and one on the trunk. In four patients, the primary melanoma was unknown. Seven patients had received adjuvant radiotherapy. The time between node dissection and the moment of analysis was two years for 17 patients, five years for 11 patients and ten years for ten patients. Calculated actuarially, 42 per cent of the patients were still without distant metastasis after two years and 32 per cent after five and ten years. At the time of the analysis, ten patients were alive, nine without evidence of disease and three having survived for more than five years. Remarkably, the primary tumor of all three patients was "unknown" and they had all had adjuvant radiotherapy. In pooling the data of this series with those from the literature, it appears that, of 78 patients with Stage II melanoma and deep node involvement, 12 had a disease-free survival time of more than five years after therapeutic radical groin dissection. Involvement of deep nodes does not always seem to equate with systemic disease. We think that, when there is an indication for a therapeutic groin dissection, an en bloc superficial and deep lymph node dissection is warranted.