OBJECTIVES: Hemophilia is a hereditary bleeding disorder characterized by spontaneous and traumatic bleeding requiring regular or episodic infusion of clotting factor. Taking care of a child with hemophilia (CWH) is burdensome for caregivers. For the assessment of caregivers’ burden standardized questionnaires are needed. We developed the “Hemophilia associated Caregiver Burden Scale” (HEMOCAB^TM). METHODS: Questionnaire development included: 1) item generation (two semi-structured focus groups with 11 caregivers, evaluation of existing caregiver burden scales for relevance by 16 HCPs); 2) feasibility testing (cognitive interviews with 12 caregivers) and 3) pilot-testing in caregivers of CWH with and without inhibitors < 22 years old (psychometric analysis of HEMOCAB^TM). RESULTS: Item generation resulted in a revised questionnaire containing 108 questions pertaining to 13 domains. Forty caregivers (75% mothers) completed the HEMOCAB^TM (mean age of 39.32±8.9). The majority of CWH had hemophilia A (95%), inhibitors (15%), were severely affected by hemophilia (77.5%), and had 4.83±8.9 bleeds in the last year. Caregivers reported spending 8.69±7.7 hours per month on infusion and 3.84±6.7 hours per month travelling to the hemophilia centre. Psychometric testing of the HEMOCAB^TM showed good values for reliability (Cronbach’s alpha of TOTAL score: α=.97; ‘FREQUENCY’: α=.95 and ‘BURDEN’: α=.92) and validity (convergent, known groups). HEMOCAB^TM correlated highly with the IOF (r=-.867 for total score) and revealed significant differences among caregivers of CWH with inhibitors vs. without in all domains of HEMOCAB^TM except for ‘school’. Caregivers reported highest burden in the domains ‘perception of child’, ‘emotional stress’ and ‘financial burden’. CONCLUSIONS: Based on item and scale analysis 49 items were deleted and the final HEMOCAB^TM consists of 59 items. HEMOCAB^TM is the first hemophilia-specific instrument for the assessment of caregiver burden with good psychometric characteristics in terms of reliability and validity. In a next step we will examine the sensitivity to change of the revised HEMOCAB^TM