The results of 24 cases of deep wound infection after total knee arthroplasty were reviewed. Twenty-one knees were initially treated with irrigation and debridement. Infection recurred in 15 knees. An increased infection rate occurred after irrigation and debridement in patients in whom the index prosthesis was in place more than 2 weeks. Nine knees (including 7 that had removal after irrigation and debridement) were treated with removal of the infected prosthesis, intravenous antibiotics, and delayed reimplantation. Immediate exchange was done in one knee. There were no recurrences in this group (P less than .001). The final status of the patients included 8 with fusions or resection arthroplasties and 16 with a prosthesis. The average Hospital for Special Surgery knee rating was 41 in patients without a prosthesis and 75 in patients with a prosthesis (P less than .001). The authors conclude that irrigation and debridement is not likely to be successful for treatment of infections when used more than 2 weeks after the initial arthroplasty. Also, two-stage reimplantation for the treatment of infected total knee arthroplasties gives a reliably low recurrence rate and provides a superior clinical result, compared to arthrodesis or resection arthroplasty.