AbstractMethods for isolation, cultivation and storage of entomogenous fungi and important aspects of host-pathogen relationships are briefly reviewed, focusing on specific factors which could influence the results of laboratory and field-based bioassays. The methods used for bioassay of these fungi against insects (including insect plant pests) are discussed and examples are used to illustrate the different methods used, augmenting the recent reviews on bioassay techniques by Goettel and Inglis (1997), Kerwin and Petersen (1997) and Papierok and Hajek (1997). Examples of common entomogenous fungi, including those of commercial importance, are given.