BACKGROUND: The treatment of brain metastasis is generally palliative, with whole brain radiation therapy (WBRT), since the majority have uncontrollable systemic cancer. In certain circumstances, such as single brain metastases, death may be more likely from brain involvement than systemic disease. In this group, surgical resection has been proposed to relieve symptoms and prolong survival. OBJECTIVES: To assess the clinical effectiveness of surgical resection plus WBRT versus WBRT alone in the treatment of single brain metastasis. SEARCH STRATEGY: The Cochrane Cancer Network Specialised trials register (July 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 1 2003), MEDLINE (1966 to July 2003), EMBASE (1980 to July 2003), CANCERLIT (1980 to July 2003), BIOSIS (1985 to July 2003) and SCIENCE CITATION INDEX (1981 to July 2003) were searched. References of identified studies were hand searched, as was the Journal of Neuro-Oncology over the previous 10 years and Neuro-Oncology over the past 2 years, including all conference abstracts. Specialists in neuro-oncology were also contacted. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing surgery and WBRT with WBRT alone, in patients with single brain metastasis. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: Three RCTs were identified, with 195 patients in total. No significant difference in survival was noted hazard ratio (HR) 0.74 (95% confidence interval (CI) 0.39 to 1.40, p = 0.35), although there was a high degree of heterogeneity between trials. One trial has shown surgery and WBRT to increase the duration of functionally independent survival (FIS) HR 0.42 (95% CI 0.22 to 0.80, p < 0.008). There is a trend for surgery and WBRT to reduce the number of deaths due to neurological cause odds ratio (OR) 0.57 (95% CI 0.29 to 1.10, p = 0.09). Adverse effects were not found to be statistically more common in any group. AUTHORS' CONCLUSIONS: Surgery and WBRT may improve FIS but not overall survival. There is a trend that it may reduce the proportion of deaths due to neurological cause. All these results were in a highly selected group of patients. Operating on metastases does not confer significantly more adverse effects.