Aspergilloma and invasive aspergillosis are important opportunistic infections caused by Aspergillus species, among which Aspergillus fumigatus is the most common species associated with human disease. We developed an ELISA-based antibody assay with Afmp1p, a purified recombinant antigenic cell wall galactomannoprotein of A. fumigatus. Evaluation of the test with guineapig sera against A. fumigatus and other pathogenic fungi indicated that this assay was specific for A. fumigatus.