Twenty-four strains of six Cylindrocladiella spp. were compared with respect to their morphology, nuclear ribosomal DNA (nuclear rDNA) polymorphisms, and restriction fragment length polymorphisms of A+T-rich DNA (AT-DNA). Two distinct DNA profiles were observed for the ten strains of C. camelliae/peruviana-complex studied. One profile corresponded with the type strain of C. peruviana, which was earlier regarded as a synonym of C. camelliae. Based on Southern analyses and AT-DNA, C. parva, C. elegans and C. lageniformis were confirmed to be distinct species with little intraspecific variation. Although C. infestans was shown to have some variation among the four strains studied, they could not clearly be distinguished as separate taxa. Based on general morphology, nuclear rDNA and AT-DNA polymorphisms, seven species of Cylindrocladiella are recognized.