A cell wall homopolymer – mannan has been isolated from the human pathogen yeast Candida dubliniensis CCY 29-177-1. It had M w =35,000 and optical rotation [α] 20 =+ 48.1 0 . Results of compositional and methylation analyses show that the α-1,6-linked backbone of the C. dubliniensis mannan is to 83% substituted by side chains of d.p. 1–7, mostly in the form of tri-, di-, mono- and tetramers, at O-2 and some Man residues might be substituted at O-3. Substitution of the backbone with single βMan units was detected in an important quantity. With molecular weight increasing of side chains the quantity of oligosaccharides with terminal single β-, two consecutive ββ- and three consecutive βββ-1,2-linked Man residues was more significant, reaching the maximum in the highest fraction (75%).