One form of a composition has two types of recombinant adeno-associated virus. The first type encodes a portion of Factor VIII operably linked to an expression control element; and the second type encodes a different portion of Factor VIII operably linked to an expression control element. The first and second nucleotide sequences collectively encode a functional Factor VIII protein. Another form of the composition is a recombinant adeno-associated virus containing a nucleotide sequence encoding functional Factor VIII light or heavy chain operably linked to a tissue-specific promoter.