Sex, size of the primary lesion, level of invasion at the primary site, clinical status of the regional lymph nodes at the time of diagnosis and whether or not the lymphatic or the blood vessels at the primary site were invaded by tumor cells are the prognostic factors found to influence the survival of patients with a cutaneous malignant melanoma. The last two factors were found to correlate with the level of invasion. Because of the high incidence of local recurrences after a small local excision, wide excision at the primary site of skin, subcutaneous tissue and fascia with skin graft should be the treatment of choice. The role of elective regional lymphadenectomy has to be questioned, as 51 per cent of the patients never required lymphadenectomy during the course of the disease, The higher incidence of satellitosis after such a procedure, elective lymph node dissection did not improve the survival. Therefore, it appears that regional lymph node dissection has a prognostic, rather than a therapeutic, role. From the time of the recurrence, it is clear that patients with systemic metastasis have the poorest prognosis. On the other hand, patients in whom satellitosis developed lived longer, but this was not statistically significant when compared with the survival of patients with a local recurrence or with regional lymph node metastasis; Early diagnosis should be emphasized because the two main factors that seem to influence survival are the depth of invasion and the size of the primary lesion. Finally, because the level of invasion and the status of the lymphatics and blood vessels seem to carry a high prognostic significance, each primary lesion should be examined pathologically with regard to these factors.