A beta-(1-5)-galactofuran was isolated and characterized from fraction F1S (alkali- and water-soluble) of the cell wall of most of the species of Eupenicillium. In E. cryptum, E. euglaucum and E. nepalense the galactan contained galactofuranose with different linkages in addition to beta-(1-5). Fraction F1I (alkali-soluble, water-insoluble) was an alpha-glucan in certain species while in others it was a beta-glucan. Xylose was detected in some species in F1I or in F3 (alkali-soluble at 70 degrees C). The most abundant fraction (F4), resistant to the alkali treatment, was a beta-glucan-chitin complex. Excepting this component, the beta-(1-5)-galactofuran was the polysaccharide which appeared more frequently in the cell wall of species of Eupenicillium and it may have chemotaxonomic relevance.