Abstract: In order to determine Fusarium diversity associated with spikes and grains of wheat, this study was conducted. Samples were taken from plants showing head scab symptoms and wheat grains that had been collected from different growing areas in Khuzestan, during growing seasons in 2002-2004. After being surface sterilized, samples from head and grains were placed into petri plates containing common media, selective media and blotter test. Isolated fungi were purified using single spore method and identified at the species level using different identification keys. Among the identified fungi, there were 10 different species of Fusarium including: F. equiseti, F. semitectum, F. sambucinum, F. culmorum, F. verticilioides, F. proliferatum, F. lateritium, F. subglutinans, F. xylaroides and F. camptoceras and one species of Microdochium nivale (= F. nivale). Based on the available references, all Fusarium species that were recovered in this study, are reported from wheat head and grains for the first time from Khuzestan province. Pathogenicity test of these species using point-inoculation method indicated that all species were pathogenic to wheat. Thus is the first report indicating the F. xylaroides as the causal agent of Fusarium head blight of wheat for the first time.