In molecular studies involving numerous clinical isolates of the genera Acremonium, Phialemonium and Lecytophora some of them could not be identified. To clarify the phylogenetic relationships among these fungi and other related taxa, we performed a polyphasic study based on a detailed morphological study and on the analysis of sequences of four loci: the internal transcribed spacer regions, the D1/D2 domains of the 28S rRNA, actin and β-tubulin genes. The combination of the resulting data let us propose the new genus Phialemoniopsis to accommodate the opportunistic fungi Phialemonium curvatum and Sarcopodium oculorum and two new species, Phialemoniopsis cornearis and Phialemoniopsis pluriloculosa. The taxonomy of Phialemoniopsis has not been completely resolved, however, remaining incertae sedis within the Sordariomycetes. In addition, the new species Lecythophora luteorubra, Lecythophora cateniformis and Phialemonium globosum are described and the species Acremonium atrogriseum and Taifanglania inflata are transferred to the genus Phialemonium. Lecythophora and Phialemonium are currently monophyletic genera of the families Coniochaetaceae (Coniochaetales) and Cephalothecaceae (Sordariales) respectively, according to our results. Tables summarizing key morphological features to distinguish the current species of Lecythophora, Phialemonium and Phialemoniopsis are provided.