The identity of strains identified as Trichoderma aureoviride/Hypocrea aureoviridis was reconsidered. Trichoderma aureoviride was isolated originally from a specimen identified as H. aureoviridis and thus is H. aureoviridis. The morphological and molecular characters of most strains identified as T. aureoviride differ from those of the ex-type but are more typical of T. harzianum, a member of sect. Pachybasium. Molecular data do not support inclusion of T. aureoviride in sect. Trichoderma, nor was there strong phenotypic similarity between H. aureoviridis and H. rufa. In the ITS phylogeny the T. aureoviride ex-type and other collections of H. aureoviridis form a strongly supported clade that is separate from any other recognized section of Trichoderma. Hypocrea vinosa, which was originally included in the T. aureoviride aggregate species concept, is distinct from T. aureoviride, but closely allied with H. rufa/T. viride. Trichoderma aureoviride/H. aureoviridis is a rare species, restricted to the UK and the Netherlands. We redefine T. aureoviride, limiting it to strains with very slow growth rate, effuse conidiation, and the ITS-1 and 2 sequence type D.