All hypocrealean species of the genus Geosmithia are anamorphic fungi with connections to bark beetles. G. fassatiae, G. langdonii and G. obscura are described as new sympatric species associated with Scolytus carpini, S. intricatus and S. rugulosus in Central Europe. The species represent a complex of three sister taxa with affinities to G. flava that may be distinguished by differences in morphology, unique RAPD patterns and by sequences of ITS region rDNA. Intraspecific variability and habitat specificity of new species is described and discussed. The high morphological, genetic and ecological uniformity suggest that these Geosmithia spp. are recently derived. A key to all accepted hypocrealean species of the genus is provided.