The purpose of this study was to review our experience in treating acute gram-positive infections after total knee arthroplasty with debridement, component retention, and intravenous antibiotics. Thirty-one total knee arthroplasties with acute gram-positive infections, seen at our institution over a 10-year period, were treated with open debridement and component retention. Eleven (35%) of 31 patients successfully retained their components at most recent follow-up, without ongoing infection (mean, 4 years; range, 2-10 years). Only one (8%) of the 13 patients infected with Staphylococcus aureus was successfully treated, compared with 10 (56%) of 18 patients with either Staphylococcus epidermidis or a streptococcal species. The difference between these groups is statistically significant (P=.007). The high failure rate of debridement and component retention suggests that immediate component removal should be considered in the presence of acute S. aureus infection in total knee arthroplasty.