SUMMARY: Cell walls were prepared mechanically from both hyphae and conidia of Penicillium chrysogenum. The major carbohydrate components of cell wall hydrolysates were glucose, galactose and glucosamine, with lesser amounts of mannose and rhamnose. The conidia were richer in galactose and the hyphae contained more glucosamine. The distribution of the monomers in acid-soluble and alkali-soluble fractions was different in the two kinds of cell wall; conidial walls contained higher concentrations and a greater variety of amino acids than hyphal walls.