A questionnaire-based follow-up study of 150 Finnish patients with coagulation disorders was conducted to evaluate the changes in clinical manifestation of the disease, pain intensity, functional disability and patient's health-related quality of life, occurring during a 3-year period. Health-related quality of life was assessed using the MOS-36 health survey. The clinical severity of the disease manifestation was estimated using the frequency of bleeding episodes into joints and soft tissue during the previous 12 months. Severity of musculoskeletal morbidity, which reflects simultaneous presence of pain and disability, was estimated using intensity of pain and level of disability. Results showed that clinical severity of the disease remained unchanged during the 3-year period for the majority of patients. Nonetheless, the annual number of bleeds in patients with severe or moderately severe haemophilia was still disconcertingly high and the number of bleeding episodes into soft tissue had increased. The clinical severity of the disease manifestation, rather than the severity of the disease based on molecular classification, was a factor that negatively influenced the intensity of pain (both acute and chronic), as well as level of disability. Severity of musculoskeletal morbidity at time 1 and changes in severity of musculoskeletal morbidity over time were found to be significant predictors of physical role, bodily pain, vitality and social functioning. In conclusion, the disease can be relatively well controlled by the availability of coagulation products, thus stabilizing the clinical severity of the disease manifestation during the 3-year period studied. The findings stress the importance of preventing haemorrhages to avoid resulting permanent joint impairment and disability.