From December 1991 to July 1993, 22 consecutive patients with grade IIIA-IIIAB melanoma underwent isolation perfusion with TNF-alpha (0.5-4 mg), melphalan (10 mg/l perfused limb) and, in the first 12 cases, IFN-gamma (1.5 x 10(6) U). The first series of 12 patients received a total dosage TNF-alpha of 2-4 mg, and the second series of 10 cases received an escalating dosage of TNF-alpha (1.5-1.0-0.5 mg) and no IFN-gamma before or during surgery. The perfusion lasted 90 min and was conducted in mild hyperthermia (39-39.5 degree C muscle temperature). The results of the first series included seven patients in complete remission, four with stable disease and one case not evaluable for local toxicity. Fifty per cent of cases developed a regional relapse from 3 to 4 months after surgery. Presently with a median follow up of 10 months, five patients of this group have no evidence of disease, four are alive with disease, two died from melanoma and one died of complications likely due to treatment (multi-organ failure syndrome). In the second series, the immediate responses included seven patients in complete remission and three in partial remission; with a median follow up of 3 months, two patients developed a regional relapse, respectively, 3 and 5 months after surgery. So far our experience of perfusion with TNF-alpha has not reproduced the data reported by other investigators. Further clinical and biological findings and a longer follow-up period are needed to draw any conclusion, and a decreasing TNF-alpha dose should be carefully evaluated.