OBJECTIVES: Acquired hemophilia (AH) is a rare disorder (1 per 1.3 million) characterized by auto-antibodies to factor VIII. AH is characterized by life-threatening bleeding and high mortality. Recombinant factor VIIa (rFVIIa) received FDA approval for treatment of AH in 2006.  As part of the post-approval commitment, Novo Nordisk agreed to use a society-owned research registry to monitor treatment of AH bleeding episodes. This required IRB approval and informed consent. For sites with few patients and/or limited research staff, the registry was not a feasible option METHODS: An alternative web-based, IRB-exempt reporting method, Acquired Hemophilia Surveillance (AHS, www.novosevensurveillance.com), was established to collect data on rFVIIa use in AH and associated adverse events under the HIPAA safety surveillance waiver.  RESULTS: From April 2008-January 2011, 32 reporters submitted 80 case reports (32 male/48 female). The mean age was 65 years (range 16-97). Common associated conditions were autoimmune disorders (32 patients), malignancy (6 patients) and post-partum state (5 patients). On average, 5 discrete bleeding events per patient (range 0-100) were reported; 75  case reports described bleeding as spontaneous (88%), surgical (16%), and/or related to a procedure (15%). No bypassing agent was reported to have been used in 17 (21%). rFVIIa was used in 50 (63%), the majority of which were first-line (39, 78%). AH was reported to have been “resolved” in 44 (55%), “not resolved” in 19 (24%), and “unsure” in 16 (20%); mean(median) time to resolution was 7.2(2) months (range 1-52). There were no reported deaths. None of the 50 rFVIIa-treated cases suffered an adverse or thrombotic event (AE). CONCLUSIONS: AHS provides an innovative approach for hemophilia treatment centers and hematology/oncology practices to capture basic safety surveillance data for patients with Acquired Hemophilia. The AHS project provides additional information about AH treatment, and reaffirms the safety of rFVIIa and the low rate of thrombotic complications.