Rotating-platform, mobile-bearing total knee arthroplasty was initially developed using a posterior cruciate-sacrificing technique and design. Posterior cruciate-substituting and -retaining, rotating-platform total knee arthroplasty designs were developed later. The purpose of this study was to evaluate a minimum 4-year follow-up of total knee arthroplasty performed with a posterior cruciate-retaining, rotating-platform design.The 4- to 6-year results of 123 patients undergoing 152 consecutive total knee arthroplasties using a posterior cruciate-retaining, rotating-platform design were evaluated. Patients were evaluated clinically for need for revision, and clinical outcome measures included the pain and functional components of the Knee Society Score, the Western Ontario and McMaster Universities Osteoarthritis Index, the Short Form 36 Health Survey, and the University of California Los Angeles activity-level scores. Radiographs were evaluated for loosening, component positioning changes, femoral-tibial alignment, and osteolysis. One knee was lost to follow-up at an average of 5.2 years. No tibial or femoral components required revision. Three polyethylene liners were revised: 2 for infection and 1 for bearing spinout. Average range of motion was 120° (range, 70°-135°). Minor areas of osteolysis were noted around 4.5% of knees, and minimal incomplete radiolucencies were noted around 50% of components. The posterior cruciate-retaining, rotating-platform knee prosthesis demonstrated excellent survivorship at 4- to 6-year follow-up.