From January 1984 to December 1986, 94 patients with unresectable, locally advanced, non-small cell lung cancer (NSCLC) were treated to assess both the efficacy and the toxicity of a combined modality treatment including radiation therapy (45 Gy/15 fractions/3 weeks) and daily low dose cDDP (6 mg/m2). The overall response rate for the 90 evaluable patients was 54.3% with 16.6% of complete responses. At a minimum follow-up of 4 years, the overall median survival time was 12 months. Provided adequate hydration is ensured, the cDDP regimen chosen as a radiosensitizer can be safely combined with radiation therapy.