Randomized trials have established the efficacy of focal treatment (either stereotactic radiosurgery or conventional surgery) for single brain metastases. In the past, adjuvant whole brain radiation therapy (WBRT) was routinely given with focal therapy. Recently, the utility of adjuvant WBRT has been called into question. This paper examines the scientific evidence and the arguments, pro and con, concerning the use of adjuvant WBRT in association with stereotactic radiosurgery or conventional surgery.