This study compared the results of total knee arthroplasty (TKA) in patients with stiff knees and patients with good preoperative range of motion. Results following TKA were compared in 30 patients (52 knees) with severely degenerated knees with preoperative range of motion < 50 degrees (group 1) and 30 patients (50 knees) who were matched for age, gender, and diagnosis with preoperative range of motion > 90 degrees (group 2). Results were evaluated for range of motion and Knee Society score, as well as the need for extensile approaches, soft-tissue releases, additional bone cuts, and constrained prostheses. Radiographic results were evaluated for implant positioning, patellar height, and alteration in joint line. Findings indicated that although TKA in stiff knees can be successful, the results are inferior to those obtained in standard TKA. Careful preoperative planning and meticulous surgical technique are essential for good results.