OBJECTIVES: Health-related quality of life (HRQL) and its impact upon productivity have not been well documented among hemophilia patients, nor among their caregivers. This study of hemophilia patients with inhibitors assessed patient and family caregiver productivity and the impact of patient HRQL. METHODS: Inhibitor patients who participated in a patient forum were mailed a survey including questions on clinical and demographic characteristics, aspects of medical care, HRQL (via the SF-12 v2), and productivity. 53 of 90 surveys were returned. Regression analyses assessed the association of patient and treatment factors with HRQL mean physical (PCS) and mental (MCS) composite summary scores and patient and caregiver productivity (missed and low productivity days in the past year). RESULTS: Patient mean age was 20.7 years (SD=18.8), 88.5% were type A, and 39.6% received on-demand therapy as their only treatment mode.  On-demand treatment (B = -0.336, P<0.05) and number of hemorrhages (B = -0.366, P<0.05) were negatively associated with PCS; and PCS was associated with patients’ missed work/school days (IRR=0.93, P<0.001) and perceived impact on daily activities (OR=0.72, P<0.05).  PCS (IRR=0.94, P<0.01), hemorrhages (IRR=1.05, P<0.05), surgery (IRR=2.74, P<0.05), and younger age (IRR=0.91, P<0.01) were associated with patients’ low productivity days. Patient surgery was associated with more caregiver missed days (IRR=3.70, P<0.05) and more caregiver low productivity days (IRR=8.99, P<0.001).  Patient MCS was also associated with caregiver low productivity days (IRR=0.96, P<0.01). CONCLUSIONS: Physical aspects of HRQL among hemophilia patients with inhibitors impact their daily activities and productivity; mental aspects of HRQL affected the productivity of family caregivers.