The first decade of the 21st century has been declared the "Bone and Joint Decade" by 35 nations and 44 states in the United States as of March 2001. It is not surprising that Americans are interested in musculoskeletal disease and the treatment of bone and joint disorders because our population is aging, the prevalence of arthritic joints is increasing, and senior Americans are demonstrating a strong desire to stay active in activities of daily living and athletics. One of the most successful treatments for painful arthritic joints, which limit activity, is total joint replacement, which predictably relieves pain and improves function. Much has been written about the technical aspects of total joint arthroplasty. Less has been written about safe and appropriate activities for patients who have had joint replacement operations. This article evaluates athletic activity after joint replacement by reviewing the orthopaedic literature and surveying members of The Hip Society, The Knee Society, and The American Shoulder and Elbow Surgeons Society. The authors have developed consensus recommendations for appropriate athletic activity for patients who have had joint replacement operations. This article is intended to serve as a guide for orthopaedic surgeons and primary care physicians who give patients recommendations for athletic activity after joint replacement. This article is also intended to stimulate further research in the area of athletic activity after total joint arthroplasty.