Patients with extremity melanoma (Stage IIIA, IIIAB or Stage IV disease who have bulky symptomatic tumor located in the extremity) or patients with unresectable extremity sarcoma will undergo a double isolated limb perfusion with melphalan alone separated by approximately 4 to 6 weeks. The initial perfusion will be done with a melphalan dose of 6 mg/L limb volume and the interval perfusion with a dose of 9 mg/L limb volume. For patients with extremity sarcoma the tumor will be excised if feasible using a limb sparing resection between 6-12 weeks after the second perfusion. Technical feasibility of the double perfusion schedule will be determined. Overall response, duration of response, patterns of recurrence, and survival will be followed.