Introduction: Differences in treatment and outcome have been reported for persons with haemophilia (PWH) on intermediate-dose (Dutch) and high-dose (Swedish) prophylaxis, but the potential influence of sports participation has not been considered. Aim: To compare sports participation and clinical outcome between adult Dutch and Swedish PWH. Methods: Self-reported sports participation (type and frequency per week), physical functioning (SF-36 PF : 100-0), joint status (HJHS: 0-144), perceived limitations (HAL sum : 100-0) and physical activity (IPAQ) were recorded. Sports were classified according to National Haemophilia Foundation classification (5 categories, highest two were classified as high-risk sports). Sports participation and clinical outcome were compared according to country and age (18-22, 23-29, 30-40 years) using non-parametric tests and Spearman correlations (rho). Results: Seventy-one adult PWH (NL: 43, SWE: 28) completed sports questionnaires (mean age: 26 years). All participants engaged in sports, including 59.2% in high-risk sports (33.9% twice weekly). Dutch PWH showed a significant age-related decline in (high-risk) sports participation (7x/wk in PWH 18-22 years to 2x/wk in PWH 30-40 years, P < 0.05), joint health (HJHS: median 2-15.5, P < 0.01) and physical functioning (SF-36 PF : median 100 to 77.5, P < 0.01), while Swedish did not. Sports participation was not associated with bleeding (Spearman's rho = −0.119). Conclusion: All participants reported sports participation, including 59.2% in high-risk sports. Dutch PWH treated with intermediate-dose prophylaxis showed an age-related decline in sports participation, joint status and physical functioning, whereas Swedish PWH on high-dose prophylaxis did not. Sports participation was not associated with bleeding.