Infected knee replacement is a serious complication that requires significant hospital-based resources for successful management. A successful primary exchange revision technique offers decreased morbidity for the patient by eliminating a second major operation and associated hospitalization, which in turn substantially reduces the cost associated with this dreaded condition. Twenty-two consecutive infected primary total knee arthroplasties in 22 patients were treated with primary exchange revision arthroplasties using antibiotic-impregnated cement. The surgical technique consisted of excision of draining sinuses, complete synovectomy, removal of granulation tissue, and debulking of the extensor mechanism. Postoperative treatment consisted of 4 to 6 weeks of parenterally administered antibiotics and 6 to 12 months of orally administered antibiotics. Both gram-positive and gram-negative organisms were treated. At an average follow-up of 10.2 years (range, 1.4 to 19.6 years), 90.9% were free of recurrent infection. Knee scores averaged 79.5, with 85.7% good or excellent results. The physiological classification of the host appeared to influence the outcome of revision. All patients in class A or B (20 knees) had successful eradication of their primary infection after 1-stage revision, whereas the only failure in the group was a physiological class C patient, who eventually expired from ongoing end-organ liver failure. These results compare most favorably with those of delayed-exchange revision arthroplasty while providing a more cost-effective management program.