The authors studied 75 patients with 158 areas of bone metastases from breast cancer treated by radiation therapy. The treatment regimen used was usually 2000 to 2500 rads delivered over a period of 2 weeks. Both subjective and objective responses were evaluated. This dose schedule proved to be highly effective in symptomatic relief and in healing osteolytic lesions; various levels of pain relief for about one year were observed in 96% (151/158 treatment areas), and radiographic evidence of recalcification was observed in 78% (73/94 treatment areas examined by serial radiography). After cases from previous studies were incorporated, the subjective response rate of the overall group was 91% (191/212) for a mean duration of 12 months, and the objective response rate was 75% (151/202) for a mean duration of 9 months.