As more and more nations are scrutinizing their health care costs, attention has been focused on high-cost low-density disease. Assessment of actual total cost of care for haemophilia and its positive outcome becomes essential to justify support for these patients. In this study, we assessed hospital cost and diagnosis-related group (DRG) reimbursement for patients undergoing elective orthopaedic surgical procedures from May 1999 to December 1999. Hospital cost was assessed by a prospective microcost-analysis method. To identify real hospital costs, we performed registration of preoperative phase, operative phase and 1-year follow-up costs. Hospital cost included personnel costs and costs for clinical and laboratory procedures, blood products, prosthetic implants, coagulation factor concentrates and drugs. These data were compared with hospital DRG reimbursement. We included nine consecutive patients, with a mean age 38 years (19-54 years) who had had 10 major orthopaedic surgical procedures performed during the study period. Six patients had haemophilia A, two had haemophilia B and one had factor VII deficiency. Data analysis showed a mean cost of US$ 54,201 (range US$ 25,795-105,479; 1US$ = 8.5 NOK). The average actual hospital revenue (50% DRG reimbursement + income related to length of stay) was $4,730 (range $ 1,308-13,601). Our study confirms that orthopaedic surgery in patients with severe bleeding disorders puts the hospital to a considerable expense. Activity-based financing, as used in Norway, does not provide a proper reimbursement for this part of the haemophilia care.