Genotyping efforts in hemophilia A (HA) populations in many countries have identified large numbers of unique mutations in the Factor VIII gene (F8). To assist HA researchers conducting genotyping analyses, we have developed a listing of F8 mutations including those listed in existing locus-specific databases as well as those identified in patient populations and reported in the literature. Each mutation was reviewed and uniquely identified using Human Genome Variation Society (HGVS) nomenclature standards for coding DNA and predicted protein changes as well as traditional nomenclature based on the mature, processed protein. Listings also include the associated hemophilia severity classified by International Society of Thrombosis and Haemostasis (ISTH) criteria, associations of the mutations with inhibitors, and reference information. The mutation list currently contains 2,537 unique mutations known to cause HA. HA severity caused by the mutation is available for 2,022 mutations (80%) and information on inhibitors is available for 1,816 mutations (72%). The CDC Hemophilia A Mutation Project (CHAMP) Mutation List is available at http://www.cdc.gov/hemophiliamutations for download and search and will be updated quarterly based on periodic literature reviews and submitted reports.