Backround. The purpose of the trial was to evaluate the effect on length of stay of individually tailored rehabilitation for clients who were undergoing hip or knee arthroplasty. Method. Clients (n = 133) with complex needs (comorbid conditions or limited social support) were randomly assigned to receive preoperative usual care (UC) or rehabilitation (R). Usual care clients received a single preoperative clinic visit. Rehabilitation clients were individually assessed and received multi disciplinary rehabilitation to optimize functional capacity, education about the in-hospital phase and early discharge planning. All rehabilitation subjects received interdisciplinary counseling/education focused on preparation for discharge home. The intervention for approximately half the rehabilitation clients was a single, cost-effective session, while others received physical conditioning. Results. Clients receiving rehabilitation achieved discharge criteria earlier (R = 5.4, UC = 8 days) and had a shorter actual length of stay (R = 6.5, UC = 10.5 days). Clinical Implications. This preoperative, individually tailored, rehabilitation program reduced length of stay.