Purpose: To determine if the addition of carboplatin chemotherapy to whole brain irradiation improves response and survival in patients with brain metastases from non-small cell lung cancer (NSCLC). Patients and methods: Forty-two patients with brain metastases from NSCLC and performance status ECOG 0-2 were randomised to receive either whole brain radiotherapy (WBRT) alone (20 Gy in five fractions) or the same radiotherapy plus concomitant carboplatin (70 mg/ml intravenously for 5 days). Results: The median survival was 4.4 months in the radiotherapy atone (RT) arm and 3.7 months in the combined treatment (RTC) arm (P = 0.64). The objective response rates of 10% on the RT arm and 29% on the RTC arm were not significantly different (P = 0.24). The trial was closed early because of poor accrual. Conclusions: Although no firm conclusions can be made regarding the efficacy of the combined treatment, this prospective study highlights the poor objective response rates and relatively poor symptom control despite standard treatment of brain metastases from NSCLC. (C) 2004 Elsevier Ireland Ltd. All rights reserved.