OBJECTIVES: Despite the clearly evident better clinical outcomes with prophylaxis compared to on-demand therapy, on average only 55% of patients diagnosed with severe hemophilia receive prophylactic factor replacement therapy in the US. Prophylaxis generally drops with age, partly due to patients becoming more independent and less compliant as they reach adulthood and partly due to reduced perceived benefit. High treatment costs of prophylaxis therapy also remains a barrier. Further, the development of long-acting factor products offering a modest improvement in convenience is likely to drive-up treatment costs. This study aims to understand hemophilia patient preferences and their willingness-to-pay for hemophilia therapies (on-demand, standard prophylaxis, longer-acting prophylaxis). METHODS: U.S. adult patients and caregivers of children with hemophilia (n = 79) completed a discrete-choice survey that presented a series of trade-off questions, each including a pair of hypothetical treatment profiles, that had an assigned cost for attaining improvement in health states. The relative importance of treatment attributes such as out-of-pocket treatment costs, dose adjustment, treatment related complications and clinical efficacy & dosing regimen was analyzed using mixed logit models. Based on the attribute estimates, patients’ WTP was determined. RESULTS: Out-of-pocket treatment costs (P < .001),  treatment complications (P < .001) and clinical efficacy & dosing regimen (P < .001) were perceived to be the most important treatment attributes. Patients were willing to pay on average $150 per/month for improvement in each of the prophylaxis dosing regimens (i.e. 3 times weekly vs 2 times weekly vs. 1 time weekly vs. 1 time in two weeks). CONCLUSIONS: The results suggest that patients are willing to pay more for improvements in treatment related complications, clinical efficacy & dosing regimen.  These estimates of patients’ willingness-to-pay can be used to provide guidelines for resource allocation. Literature also suggests that patient preferences are likely to directly translate into increased treatment adherence, leading to greater treatment effectiveness.