Drechmeria coniospora is a nematophagous fungus and potential biocontrol agent. It belongs to the Ascomycota. It is related to Hirsutella minnesotensis, another nematophagous fungus but, phylogenetically, it is currently closest to the truffle parasite Tolypocladium ophioglossoides. Together with its natural host, Caenorhabditis elegans, it is used to study host-pathogen interactions. Here, we report a polyethylene glycol-mediated transformation method (Turgeon et al., 2010; Ochman et al., 1988) for this fungus. The protocol can be used to generate both knock-in or knock-out strains (Lebrigand et al., 2016).