We report on 20 patients suffering from malignant melanoma, who had undergone regional lymph node dissection. In order to make certain that all the lymph nodes had been completely removed, we performed lymphoscintigraphy 3 to 6 weeks after block dissection with the help of a radiopharmacon intercostally or interdigitally applied. We judged the removal to be complete, if neither intercostal nor interdigital application led to any evidence of regional lymph nodes. On the basis of our experiences so far, we consider postoperative lymphoscintigraphy a suitable non-invasive method to check the completeness of block dissection.