BACKGROUND It is generally accepted that prosthetic elbow replacement should be avoided in young patients because of an anticipated high rate of early failure. The purpose of this paper was to define the success, prosthetic survival rate, and problems encountered in patients who were treated with a semiconstrained total elbow arthroplasty when they were forty years of age or less. METHODS We retrospectively reviewed the records of 758 patients who had undergone primary arthroplasty with the Coonrad-Morrey total elbow prosthesis for any reason between 1982 and 2003. We identified fifty-five total elbow arthroplasties that had been performed in forty-nine patients (thirty-eight women and eleven men) who were forty years of age or less (mean, thirty-three years) at the time of the operation and that had been followed for a minimum of five years. Six patients had a bilateral procedure. The indication for the arthroplasty was inflammatory arthritis in thirty patients and posttraumatic arthritis in nineteen. Patients with hemophilia or a neoplasm were excluded. The medical record data were used to calculate the preoperative and postoperative Mayo Elbow Performance Score. RESULTS The mean duration of follow-up was ninety-one months. During this period, twelve (22%) of the elbows had undergone a subsequent surgical procedure: four because of loosening, three because of triceps weakness, three because of wear, and two because of deep infection. On the basis of the Mayo Elbow Performance Score at the last review, thirty-six results (65%) were considered to be excellent; fifteen (27%), good; three (5%), fair; and one (2%), poor. CONCLUSIONS Semiconstrained total elbow arthroplasty in young patients was associated with a 22% revision rate at a mean of ninety-one months, and the rate of revision was significantly higher for patients with posttraumatic arthritis. Despite this revision rate, fifty-one elbows (93%) had a good or excellent Mayo Elbow Performance Score.