Brain metastases are common in cancer patients and cause considerable morbidity and mortality. For patients with limited disease and good performance status, treatment typically involves a combination of focal measures (e.g., surgical resection or radiosurgery) for the radiographically apparent disease, followed by adjuvant whole brain radiotherapy (WBRT) to treat subclinical disease. Because of concerns regarding the toxicity of WBRT, especially neurocognitive deterioration, many have advocated withholding adjuvant WBRT. Recently published studies have shed more light on the efficacy of adjuvant WBRT and the neurocognitive effects of WBRT. However, the inclusion of neurocognitive and quality-of-life data in clinical trials are still required to better define the role of adjuvant WBRT. Currently, two Phase III trials are underway, one in Europe and one in North America, that will determine the effect of adjuvant WBRT on patients' quality of life, neurocognitive function, and survival.