AbstractThe genusSchizosaccharomycescomprises a small, somewhat heterogeneous group of yeast species which have in common a unique mode of vegetative reproduction by cross‐wall formation without constriction as well as a certain degree of osmophilia, most strains having been isolated from habitats of high sugar concentration. This study evaluated inter‐ and intraspecific relationships utilizing nDNA/nDNA optical reassociation and by the analysis of physiological profiles of several strains of each species. Results demonstrate that the genus should be divided into three species:Schiz. japonicus,Schiz. octosporusandSchiz. po