Thirty-six patients with Stage IV renal cell carcinoma were treated with autolymphocyte therapy (ALT). This new form of adoptive immunotherapy is based on the infusion of relatively small numbers of autologous lymphocytes that are depleted of suppressor cells and immunized in vitro by a method designed for antigen-specific activation using a 3M KCl extract of autologous tumor and an autologous lymphokine mixture. Patients received six monthly infusions of immunized lymphocytes, all on an outpatient basis. The majority of patients experienced no toxicity. The few reactions that occurred were minor and self-limiting; none required any medical intervention or subsequent delay in therapy. Patients also received oral cimetidine to reduce in vivo suppressor cell function. Survival at twenty-four months is 36 percent. Median survival is fifteen months, a significant improvement over the natural history of this disease. A multi-site, randomized, controlled trial of ALT in renal cell carcinoma has been initiated to confirm that this treatment causes a significant prolongation of survival with virtually no toxicity in these patients.