tDetection of carbohydrate antigens is an important means for diagnosis of invasive fungal infections. Fordiagnosis of systemic Aspergillus infections, galactomannan is commonly used, the core antigenic struc-ture of which consists of chains of several galactofuranose moieties. In this study, we provide evidence thatFusarium produces at least two distinct galactofuranose antigens: Smaller amounts of galactomannanand larger quantities of a novel antigen recognized by the monoclonal antibody AB135-8. In A. fumiga-tus, only minor amounts of the AB135-8 antigen are found in supernatants and in the apical regions ofhyphae. A galactofuranose-deficient A. fumigatus mutant lacks the AB135-8 antigen, which strongly sug-gests that galactofuranose is an essential constituent of this antigen. Using a combination of AB135-8 anda galactomannan-specific antibody, we were able to unambiguously differentiate A. fumigatus and Fusar-ium hyphae in immunohistology. Moreover, since Fusarium releases the AB135-8 antigen, it appears tobe a promising target antigen for a serological detection of Fusarium infections.