We reviewed the results, in eight patients, of excision of heterotopic ossification about the elbow performed three to ten months (average, seven months) after the initial injury and followed by radiation therapy to prevent recurrence. The etiology of the heterotopic ossification included a neurological (head or spinal cord) injury in five patients and a local injury (fracture or fracture-dislocation) of the elbow in three patients. The average preoperative arc of motion of the three joints that were capable of motion was 12 degrees (5, 10, and 20 degrees); the remaining five joints were fixed in an average of 56 degrees (range, 10 to 90 degrees) of flexion.All of the patients received a total dose of radiation of 1000 centigray, divided into five fractions. The radiation therapy was instituted on the first postoperative day, and at least three of the remaining four treatments were administered on consecutive days. Radiation therapy was not performed on the weekend, so the five fractions were administered over the course of seven days.At an average of forty-six months (range, twenty-five to seventy-two months), the arc of motion averaged 103 degrees, which compared favorably with the 121-degree arc of motion that had been attained intraoperatively. Two patients who had residual motor deficits in the involved extremity had an arc of motion of 50 and 70 degrees at the latest follow-up evaluation; those who had normal motor function fared considerably better, averaging 118 degrees of motion. There was no substantial recurrence of ossification either radiographically or that limited motion, and no complications attributable to the radiation therapy were noted.On the basis of this experience, it seems that the generally recommended twelve to eighteen-month delay between injury and excision, to allow for maturation of heterotopic bone and thus to lessen the likelihood of recurrence, may be eliminated. Additional studies are needed to define the relative risk of recurrence in the various clinical settings in which heterotopic ossification is seen and to determine whether radiation therapy is necessary to prevent recurrence after early excision in each of these instances.