CDDP is one of the most active single drugs in non small cell lung carcinoma. High doses of 200 mg/m2 are well tolerated when fractionated doses are used over a period of 5 d. Twenty-four consecutive patients (male, age range 38-70 y) with brain metastasis of lung carcinoma were included in this study. The total dose of CDDP - 200 mg/m2 - was divided into 5 equal daily fractions, infused over 6 h. Parenteral hydratation commenced the night before therapy. Efficiency was assessed by means of CT scan 15-30 d after the last course of chemotherapy. Complete response was achieved if no lesion was found on the CT scan; partial deafness 2 cases, renal toxicity 1 case, severe myelotoxicity 2 cases. Efficiency: failure was observed in 17 cases, objective responses in 7 cases (2 cases without injection contrast in the tumor, 3 partial regressions, 2 complete regressions). Thirty per cent of patients in this study exhibited an objective response with low toxicity. CDDP seems to be very useful in cerebral metastasis of lung carcinoma.