INTRODUCTION: The Haemophilia Activities List (HAL) and paediatric HAL assess self-reported limitations in various daily activities. To reduce patient burden, shorter versions of the pedHAL (22 items) and HAL (18 items) have been developed. AIM: This study aimed to determine the agreement between the pedHAL/HAL full and pedHAL/HAL short and construct validity and internal consistency of the pedHAL / HAL short in persons with haemophilia (PWH). METHODS: A cross-sectional secondary analysis of the Hemophilia in the Netherlands-6 national survey was performed. Adult and paediatric PWH completed the original pedHAL/HAL full , from which pedHAL / HAL short were derived. Score differences between the original and short versions were calculated. Construct validity was studied by testing hypotheses regarding the relationship of the pedHAL/HAL short with the pedHAL/HAL full , Haemophilia & Exercise Project Test-Questionnaire (HEP-Test-Q), Canadian Haemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) and RAND 36-item Health Survey (RAND-36) (convergent/discriminant validity) as well as its ability to discriminate between subgroups (known-group validity). Internal consistency was assessed with Cronbach's α. RESULTS: We included 113 children (median 10y [range 4-17], 53% severe haemophilia) and 691 adults (median 51y [range 18-88], 35% severe). Scores of the pedHAL/HAL full and pedHAL/HAL short were similar with high correlations (>0.9). Construct validity was confirmed for the pedHAL/HAL short . The HAL short was able to discriminate between different disease severities and ages. Cronbach's α of the pedHAL/HAL short was 0.95-0.97. CONCLUSION: This study confirmed the agreement between the pedHAL/HAL full and the pedHAL/HAL short and the construct validity of the pedHAL/HAL short . The next step is to study construct validity of the pedHAL/HAL short when administered as short forms.