The most common bleeding in haemophilic patients is in joints, and joint disability is the most common complications in these patients receiving inadequate treatment. Limited by economy and inadequate treatment, developing countries face huge challenge to reduce disability and improve quality of life (QoL) of haemophilic children. The aim of this study was to investigate the effect of low dose secondary prophylaxis in China. Children with moderate and severe haemophilia from the Beijing Children Hospital, Beijing, China, and with established joint disease, were followed for a 12-week observation period followed by a 12-week low dose secondary prophylaxis-study period (for haemophilia A, factor VIII concentrate 10 IU kg(-1) twice weekly; for haemophilia B, factor IX concentrate 20 IU kg(-1) weekly). The reduction of joint bleeding, improvement of joint function and QoL during prophylaxis were analysed. In total 34 children (median age 7.8 years) were analyzable. The number of joint bleeds decreased from a total of 337 (individual range 3-24, mean 9.9) during the observation period to 57 (range 0-6, mean 1.7) during the study period with an overall of reduction 83%. Joint function improved in 66.7% of disease joints, with 23.2% of which were considered good to moderate. School attendance improved in all subjects, sports participation and daily activity improved moderately. Low dose secondary prophylaxis significantly reduces frequency of joint bleeding; with moderate improvement in joint function, school attendance, sport participation and daily activities. Low dose secondary prophylaxis is therefore, cost-effective as applied to developing countries such as China, although there are still unresolved issues.