Total knee arthroplasty performed after tibial plateau fracture has a known high rate of complications. We hypothesized TKAs performed after infected tibial plateau fractures would have an even higher complication rate when compared with noninfected tibial plateau fractures. In a matched case-control study, we retrospectively reviewed 19 patients who underwent primary TKAs after infected tibial plateau fractures between 1971 and 2005. The mean time from the most recent infection to arthroplasty was 5.6 years. The minimum clinical followup after TKA was 2 years (mean, 6.4 years; range, 2–15.1 years). Case patients were matched for age, gender, and arthroplasty year with 19 control subjects who underwent TKAs for tibial plateau fractures with no history of infections. After surgery, the Knee Society scores for the study group improved from 45 to 63 for pain and from 37 to 63 for function. Ten case patients (53%) sustained complications, including surgery for wound breakdown (three), manipulation (one), aseptic loosening (two), definitive resection arthroplasty (two), and above-knee amputation (two). Recurrent infections occurred in five patients (26%) at a mean of 1.1 years. Previously infected knees were 4.1 times more likely to require additional procedures compared with knees with no previous infection.