BACKGROUND The purpose of this retrospective study was to analyze the utility of a trochanteric claw plate in the treatment of an ununited greater trochanter following total hip arthroplasty. METHODS From 1986 through 1999, seventy-two consecutive procedures to reattach an ununited greater trochanter were performed in seventy-one patients. The average age at the time of the index arthroplasty was 66.2 years. The arthroplasty that resulted in the nonunion of the greater trochanter was primary in fifty-four hips, a first revision in sixteen hips, and a second and third revision in one hip each. The mean duration between the hip replacement and the treatment of the nonunion was 8.1 months. The greater trochanter was fixed with the trochanteric plate alone in forty-eight hips and with the plate in conjunction with vertical wires in the remaining twenty-four hips. The average duration of followup was 5.1 years. RESULTS Osseous union occurred in fifty-one of the seventy-two hips. There was a persistent nonunion in twelve hips and fibrous consolidation in the remaining nine hips. The mean time to osseous consolidation was 3.7 +/- 2.1 months (range, two to twelve months). The mean Merle d'Aubigne hip score was 16.1 +/- 2.4 points at the time of the latest follow-up. A highly significant improvement in function was achieved only in the group with osseous consolidation (p < 0.0001). The highest rate of osseous union was achieved when vertical wires had been used in conjunction with the claw plate. Union occurred in twenty-one of the twenty-four hips in that group (p = 0.025). CONCLUSIONS Nonunion of the greater trochanter following total hip arthroplasty can be successfully treated with a trochanteric claw plate. The use of adjunctive vertical wires results in better osseous contact and union.