Transmission electron microscopy of ultrathin sections of hyphal cells of Basidiobolus haptosporus and B. ranarum revealed the presence of particulate inclusions consistent in morphology with that described in certain other fungi as virus-like particles. Two types of particles were observed which differed in substructure and distribution within the host cytoplasm. Relative numbers of these particles were never great, and their presence in the host was not associated with any demonstrable cytopathological changes detectable at the ultrastructural level. We believe this report to be the first description of an association of virus-like particles with fungi of the Entomophthoraceae.