Thirty-one patients with metastatic brain tumors (MBT) from lung cancer and ten patients with MBT from melanoma received BCNU, 100 mg/m2, every four weeks by intracarotid and/or vertebral artery infusion into each involved site. Twenty-five patients with lung cancer and all melanoma patients are currently evaluable. Twelve patients with lung cancer had complete and partial responses lasting from 1 to 14 months. Four of them with the histologic diagnosis of small cell carcinoma, one with large cell carcinoma and one with squamous cell carcinoma showed complete response. None of the patients with melanoma MBT experienced any response. All of the patients had periorbital erythralgia and/or occipital pain during the infusion. Four patients manifested mild focal seizures during the infusion or 6 to 24 hours after the treatment. Transient confusion with disorientation was observed in two patients 4 and 24 hours, respectively, after a BCNU infusion. Two patients developed reversible thrombocytopenia after the fifth course of the IA chemotherapy. Median survival of patients with MBT from lung carcinoma was 4 months, with two of them still alive at 10 and 14 months, respectively. Only one patients of the 25 with lung carcinoma died from MBT. Failure to control the primary disease resulted in the deaths of a vast majority of the patients.