A phase II study was conducted in order to determine the feasibility and toxicity of cisplatin combined with the nitrosourea fotemustine in central nervous system metastases from non-small cell lung cancer. 31 chemotherapy-naïve patients were included between November 1990 and April 1993. Computed tomography scan-documented tumour regression in brain metastases was observed in 7 of the 25 evaluable patients, but only 4 of these (16%) lasted more than 4 weeks. In 2 of these 4 patients, the response on central nervous system metastases was considered as complete. The median duration of response was 20.5 weeks and the median survival was 16 weeks overall and 28.5 weeks for responding patients. The limiting toxicity of this regimen was haematological. 2 patients died from infectious pneumonitis while in neutropenia. Treatment delays due to haematological toxicity occurred in 57% of patients. Despite the rather encouraging response rate, such toxicity appears too high when compared to the overall bad prognosis of this population of patients. Cranial radiotherapy remains the standard treatment in this setting and should only be compared in the future to less aggressive schedules.