We evaluated adoptive cellular therapy with recombinant interleukin-2 (rIL-2) plus lymphokine-activated killer (LAK) cells alternating with sequential dacarbazine chemotherapy in 27 patients with metastatic melanoma. rIL-2 was given to the patients as a 5-day continuous-infusion priming cycle followed by 1 day of rest, 4 days of leukapheresis for in vitro LAK cell expansion, and then 4 1/2 days of continuous rIL-2 infusion in conjunction with reinfusion of LAK cells during the first 3 days of the continuous infusion. Two weeks later, patients received dacarbazine (1,200 mg/m2) chemotherapy. Two patients achieved complete remission, and five achieved a partial remission for a response rate of 26% (95% confidence interval = 12%-47%). Three patients had mixed responses. The partial and mixed responses were brief, ranging from 1 month to 6 months, whereas the two complete responses have been sustained for 13+ and 24+ months. There were no additive toxic effects except for thrombocytopenia, which delayed treatment in two patients. Alternating adoptive immunotherapy and dacarbazine chemotherapy appear to be reasonably tolerated by patients, but the response rate is not clearly better than that achieved with other rIL-2 regimens or with chemotherapy alone.