Fifty-four patients with inoperable cancers were treated with a combination of cisplatin and radiotherapy from May 1984 to February 1989. Cisplatin was administered at a dose of 40 mg/week, for a total dose of 160-320 mg, during radiation therapy. In 4 cases with brain metastases, the cisplatin dose was 40 mg/m2. Cisplatin concentration in blood was measured using the flameless atomic absorption spectrophotometric method. Radiation therapy was delivered by a 6 MV X-ray or a cobalt-60 unit up to a total dose of 50-70 Gy. Among the 54 patients, 89% (48) responded to the treatment regimen; complete responses (CR) and partial responses (PR) were 56% and 33%, respectively. Six patients were stable in their disease. Among the 30 patients who had CR's, the 1-year survival rate was 88% (21/24). Two patients (7%) had local relapse. However, among PRs, the 1-year survival rate was 33% (4/12) and local failure (61%) (11/18). Objective tumor response was observed in 4 cases with brain metastasis, 2 of the 4 patients were alive for more than 6 months. Toxic effects were moderate and consisted of emesis and myelosuppression. Grade III bone marrow suppression amounted to 11%, and the interval of recovery was relatively long compared with that reported in the literature. Further prospective controlled studies are recommended.