The use of radiotherapy to treat metastatic bone pain is being challenged by claims of high cost and by more readily available, noninvasive treatment approaches. The authors assessed the effectiveness of brief courses of radiotherapy in reducing pain and estimated cost data for a pilot comparison between radiotherapy and narcotic analgesics in patients with cancer. A representative group of outpatients undergoing brief courses of radiotherapy with Karnofsky scores above 70 and without serious comorbidities were recruited from 1995 through 1996. Patients indicated their pain at rest and with movement on a scale of from 1 to 10 both before and up to 12 months after radiotherapy. Radiotherapy costs were estimated from Medicare-allowable charges. Narcotic analgesia costs were estimated from published values. In 66 patients with 131 individually treated sites, median at rest pain score decreased by about 4 points after treatment (5.58 [-/+3.28] before treatment vs. 1.55 [-/+1.8] after treatment; p < 0.05). Median with movement pain score was about 5 points lower after treatment (7.32 [-/+2.72] before treatment vs. 1.94 [-/+2.07] after treatment; p < 0.05). No differences were found when stratifying by type of pain, tumor histologic type, or skeletal site. The estimated cost per patient ranged from $1,200 to $2,500 for radiotherapy. This compares with an estimated cost of $9,000 to $36,000 for 9 months of narcotics. In this pilot study, a brief course of radiotherapy significantly reduced pain and appeared to be cost effective when compared with narcotic analgesia. A full economic evaluation is warranted.