The issue of athletic participation after hip and knee arthroplasty has become more relevant in recent years, with an increase in the number of young and active patients receiving joint replacements. This article reviews patient-, surgery-, implant-, and sports-related factors, and discusses currently available guidelines that should be considered by the physician when counseling patients regarding a return to athletic activity after total joint arthroplasty. Current evidence regarding appropriate athletic participation after total hip arthroplasty, resurfacing hip arthroplasty, total knee arthroplasty, and unicondylar knee arthroplasty is reviewed.