OBJECTIVES: Hemophilia is a bleeding disorder resulting from reduced or absent clotting factors.  Inhibitors are alloantibodies that develop in response to replacement therapy with coagulation factor products. Patients are diagnosed at birth or shortly thereafter, and care is typically provided at home by parents and relatives (i.e., caregivers). Few formal studies have explored the experience of caregivers of children with hemophilia. This study aimed to quantify the overall burden of hemophilia on caregivers using a novel questionnaire. METHODS: A questionnaire with six domains (emotional stress, financial, sacrifice, medical management, child’s pain, and transportation) and several visual analogue scales (VAS) was developed based upon the peer-reviewed literature and previous survey findings.  Survey questions were validated with 3 caregivers.    Previously developed opt-in research database was used for recruitment.  IRB approval was obtained. RESULTS: A total of 310 caregivers (out of 681 invitees) completed the survey. Most respondents were mothers (88%) between 18-54 years.  89% had at least some college education.  “Child’s pain” was the most burdensome domain (mean score=3.54 out of 5), followed by “emotional stress” (2.79), “financial” (2.52), “transportation” (2.51), “sacrifice” (2.22) and “medical management” (2.05).  Caregivers of inhibitor patients had higher total burden scores (96.17 vs. 78.65, p<0.0001) and burden VAS scores (5.57 vs. 3.44, p<0.0001) compared to those without inhibitors.  Similar trends were seen for those diagnosed with hemophilia ≤ 2 years ago versus all else (86.36 vs. 79.83, p<0.04; burden VAS 4.89 vs. 3.47, p<0.0002).   Other factors significantly impacting burden were: income ≤ $50,000, taking ≥ 6 hours off work or having >1 bleed in past month (p<0.001). CONCLUSIONS: Hemophilia caregivers are largely impacted by the burden of their child’s pain and emotional stress. Since caregivers of patients with inhibitors and those with ≤ 2 years since diagnosis were more significantly burdened, potential programs can be developed to lessen their burden.