The results of 24 modular Genesis II (Smith & Nephew, Memphis, TN, USA) total knee arthroplasties, performed in 20 patients with haemophilia were prospectively reviewed. The hypothesis that the use of a new-generation implant and advanced, more aggressive hematological care, will result in a decrease rate of complications and better functional results for the haemophilic patients with TKA was tested. The mean age at the time of surgery was 36 years (25 to 44). All the patients were reviewed clinically and radiologically with an average follow-up of 4.4 years (2 to 7 years). At the final follow-up the knee score improved from an average of 23 points (11 to 45) to 86 points (62 to 100; p<0.001). The mean knee flexion contracture improved from 22 degrees (0 degrees to 45 degrees ) to 3 degrees (0 degrees to 10 degrees ; p<0.0001). The mean total flexion arc improved from 69 degrees (5 degrees to 130 degrees ) to 92 degrees (80 degrees to 145 degrees p<0.001). The results of our study confirm that the introduction of modular design may improve the functional results of TKA in haemophilic arthropathy which results in a better range of motion and lower flexion contracture.