In this study we tried to evaluate the early functional results of high flexion total knee prosthesis in comparison with conventional total knee arthroplasty. It is non-randomized prospective study done on 60 patients all of them complaining of disabling degenerative osteoarthritis of the knee. 30 patients treated with high flexion total knee prosthesis (Nex-Gen LPS Flex) and another 30 patients treated with conventional total knee prosthesis (Nex-Gen LPS). The mean pre-operative maximum knee flexion in high flex knee group was 123.31 ͦ while in conventional knee group was 99.601 ͦ.The mean follow up period was 14.96 months. At last follow up of the patients the mean post-operative range of motion in high flex knee group was 125.2 ͦ with no significant obvious improvement than the pre-operative range of motion while in conventional knee the average range of motion 118.939 ͦ. The knee society scoring system used for pre- and post-operative assessment.