The present study compares all known species of Cylindrocladium that have clavate vesicles. Several isolates were obtained from baited soils collected in various parts of the world, while others were associated with leaf litter or symptomatic plant hosts. Isolates were compared based on morphology, as well as DNA sequence data from their ß-tubulin and histone gene H3 regions. Cylindrocladium australiense and Cy. ecuadoriae, are described as new species, a decision based on morphology and molecular data. A group of isolates associated with toppling disease of banana in the West Indies is identified as Cy. flexuosum. An epitype is designated for Cy. ilicicola, and a new name, Curvicladiella, proposed to replace the anamorphic genus Curvicladium, which is a homonym.