An account is given of species of Absidia maintained in the CBS collection. Cultures were studied on the basis of morphology, temperature relations and mating results. Synonymy is concluded for A. atrospora, A. griseola, and A. hyalospora with A. blakesleeana; A. hesseltinei with A. corymbifera. Mating activity was strong in the subgenus Mycocladus, weak or absent in the subgenus Absidia, under the test condition. A key to the species is included.