Eleven patients, pre-treated with chemotherapy and immunotherapy, with renal cell carcinoma were given 13-cis-retinoic acid (CRA) in association with interferon alfa-2a (IFN 2a). 13-ci retinoic acid was administered at the dose of 1 mg/Kg/die while interferon alfa-2a at the dose of 3X10 U.I./die s.c. All patients had been previously treated with chemotherapy in association with immunotherapy. Therapy was not discontinued until neoplastic progression occurred. Clinical results were as follows: partial responses (PR) were observed in two patients, disease stabilization (SD) in 5 and progression (PD), with 8-month median treatment duration, in 4. Side effects were mild.