OBJECTIVE To analyse the toxicity and efficacy of combined interferon-alpha and interleukin-2, administered subcutaneously in a general multicentre setting, as treatment for metastatic renal cell carcinoma. METHODS Thirty-three patients with metastatic renal cell carcinoma were scheduled to receive 2 cyclical doses of subcutaneous interferon-alpha (week 1: 5 MU x 3 days) and interleukin-2 (week 2: 36 MU x 2 days, 9 MU x 3 days; weeks 3-5: 9 MU daily). Karnofsky scores ranged from 80 to 100 (median 90). Metastases occurred in multiple organs (lung 63%, retroperitoneal 39%, liver 24%). Patients were categorised according to the risk of disease progression. Treatment toxicity, therapeutic response and actuarial survival were analysed. RESULTS All patients received recommended doses of treatment, but 6 received less than 2 cycles. Most were treated as outpatients, although hospitalisation was usual during the 1st week of a cycle. All complained of mild flu-like symptoms. Severe side effects developed in 13 patients (39%), and treatment was discontinued in 3 of these patients. No deaths occurred as a result of treatment. The overall median survival was 10 months. The overall actuarial survival rate at 3 years was 22%. On statistical analysis, actuarial survival rates were not influenced by either response to treatment or risk group category. CONCLUSION Subcutaneously administered, combined interferon-alpha and interleukin-2 therapy achieves durable survival rates in a minority of patients with renal cell carcinoma. Toxicity is remedial, and not fatal, when subcutaneous therapy is administered by multiple medical disciplines at a variety of centres.