A satisfactory range of motion is one of the important goal of total knee arthroplasty. We investigated the factors that may influence the range of motion after total knee arthroplasty in 49 arthroplasties of 36 patients with minimum follow-up of 12 months. For minimizing the effect of other variables we included only osteoarthritic patients who received primary AGC(BIOMET) knees, cemented fixation of all three component by one surgeon. Some factors that may affect final results were verified. These factors include BMI(ratio of weight and height), preoperative range of motion, preoperative X-ray findings such as sever- ity of spur change and varus deformity, early continuous passive motion trial. Statistical analysis was done by Students t test. The statistically significant factors which influenced the range of motion after arthroplasty were the preoperative flexion deformity and range of flexion, varus deformity, and spur change.