The purpose of this study was to determine whether the SF-36 general health status survey was sensitive enough to document early improvements in patient health after total hip arthroplasty (THA) and total knee arthroplasty (TKA). Early follow-up data were collected an average of 3 months after surgery. Results were striking, showing statistically significant improvements in all pain and function subcategories of the SF-36 for both THA and TKA. Further, the survey instrument successfully differentiated the course of healing after THA and TKA; at this early follow-up period, the patients who had had THA expressed greater improvement in pain, function, and overall health than did patients who had had TKA. These data suggest that the SF-36 is a simple, easy-to-administer, and effective instrument for monitoring improvements in patient health after THA and TKA.