Aim: is to present 24 years survivorship analysis of 1033 posterior cruciate retaining knee arthroplasties and to identify inherent risk factors, which can lead to higher rates of failure. Materials: 1033 primary total knee arthroplasties with posterior cruciate retention done under the supervision of one surgeon and were followed in a prospective fashion. Results: No patient was lost to follow-up. The minimum follow-up in living patients was of 10 years. Average age at surgery was 69.5 years. 89 knees (9%) had rheumatoid arthritis. Revision was done in 26 (2.5%) for failure and in 5(0.48%) knees for infection. The probability of survival of implant for revision was 95% at 15 years, 89 at 20 years and 83% at 24 years. The survivorship for OA was 82% and 94% was for RA (log rank, p=0.07). Survival for males was 89% and 81% for females (p= 0.53). The regression analysis showed length of follow-up (0.03) was signiþcant and prosthesis design (p=0.001) while age at surgery (p=0.75) and diagnosis (p=0.64) were not. Conclusion: The long term survival was 83% at 24 years of primary total knee arthroplasty. The signiþcant of length of follow-up and prosthetic designs reßects the use of the implant, and of indirectly suggestive of polyethylene wear.