OBJECTIVES: To describe health-related quality of life (HRQoL) and health utility of persons with hemophilia B, and to determine the association of these measures with self-reported joint pain and motion limitation.   METHODS: The prospective, longitudinal Hemophilia Utilization Group Study (HUGS-Vb) recruited participants with hemophilia B from six U.S. Hemophilia Treatment Centers from June 2009 to September 2010. At initial interview, participants or their parent(s) answered questions regarding demographic and clinical characteristics, HRQoL, health utility and self-reported joint pain and motion limitation. HRQoL measures included Short Form-12 (SF-12) for adults and PedsQL for children. Health utility measures used were EQ-5D (adults) and visual analog scale (VAS). RESULTS: Seventy-seven participants (48% adults) were recruited. Adult mean SF-12 mental (MCS-12) and physical (PCS-12) component scores were 54.3(±6.13) and 47.1(±11.1) respectively. Participants with mild/moderate hemophilia (mean=50.4±9.0) had significantly better PCS-12 scores than those with severe hemophilia (mean=42.6±12.4) (P=0.0390). Mean EQ-5D and VAS scores were 0.85(±0.16) and 85.5(±11.1) respectively, with no significant differences between severity groups. PCS-12 and EQ-5D each negatively correlated with self-reported joint pain (PCS-12:P<0.0001, EQ-5D:P=0.0017) and motion limitation (PCS-12:P<0.0001, EQ-5D:P=0.0081); better HRQoL was associated with less severe pain or limitation. Pediatric mean total PedsQL score was 85.6(±11.2) with physical (PF) and psychosocial functioning summary scores of 92(±14.9) and 82(±13.1) respectively. Mean VAS score was 88.6(±14.3). No significant differences were found between severity groups. PF and VAS scores each negatively correlated with self-reported joint pain (PF:P=0.0127, VAS:P=0.0245) and motion limitation (PF:P=0.0009, VAS:P=0.0015). CONCLUSIONS: While previous HRQoL studies have examined hemophilia A and its associated clinical aspects, this is the first focusing on the hemophilia B population. As hemophilia A and B may have different clinical manifestations, HRQoL data on hemophilia B can help define disease burden in this group. One limitation is the current small sample size, which will increase as additional participants continue to be enrolled.