Monoclonal antibodies (MAbs) were raised against Fusarium avenaceum and Microdochium nivale. Cross‐reactivity studies carried out against 14 different Fusarium species plus M. nivale, 10 other field fungi and eight storage fungi indicated that several cell lines had been produced that secreted MAbs specific to F. avenaceum and M. nivale. It is suggested that these specific MAbs along with other MAbs specific to F. culmorum and F. poae produced at the Central Science Laboratory, could be used in immunoassays to assist in the identification, detection and enumeration of Fusarium species and M. nivale.