The objective was to analyze the outcome of three treatment strategies using isolated hyperthermic liver perfusion (IHP) with melphalan for liver metastases of malignant melanoma. It was designed as an exploratory study. The setting was a single-center study in a university hospital. The study was carried out on 27 patients. IHP was used with modifications during three different time periods (IHP I, IHP II and IHP III), in technique and temperature (amount of melphalan: 0.5, 1.0 and 2 mg/kg body weight in the perfusate; 41, 40 and 40 degrees C). Tumor response was estimated according to WHO criteria with computed tomography or MRI. Mortality and morbidity were secondary measures. Six of 11 patients in the IHP I cohort experienced a partial response (PR). In the IHP II cohort, two patients of 11 experienced a complete response and five a PR. In the IHP III cohort, five of five patients experienced a PR. Six postoperative deaths were reported (27%) (three in the IHP I and three in the IHP II series), secondary to liver insufficiency and multiorgan failure. Treatment of liver metastases of malignant melanoma with isolated hyperthermic melphalan perfusion has shown an impressive tumor response rate, which seems to be higher than the response rates reported for other systemic chemotherapy regimens. The maximum tolerated dose for melphalan in the perfusate was surpassed with a 2 mg/kg body weight. By modifying the technique and restricting the allowed tumor burden, the response rate remained high and the mortality was reduced.