Despite the promising acute and chronic toxicity of commercial acetogenin-based bioinsecticide formulations reported for different arthropod pests and their recent registration, we are unaware of any published study that examines the compatibility of these botanical derivatives with entomopathogenic fungi, which are important natural and applied biological control agents. We investigated the compatibility of Annona mucosa Jacq. (Magnoliales: Annonaceae) ethanolic seed extract (ESAM), an effective bioinsecticide previously characterized by its high acetogenin content, with 3 entomopathogenic fungal species, Beauveria bassiana (ESALQ-PL63 isolate), Isaria fumosorosea (ESALQ-1296 isolate) and Metarhizium anisopliae (ESALQ-E9 isolate) at various concentrations in different in vitro assays. The effects of the botanical insecticide varied according to the fungal isolate exposed, the biological variable analyzed, and the concentration used. However, based on the compatibility index adopted, ESAM was classified as compatible with the above 3 fungal species, except at the highest concentration tested (8,000 mg L^-1) for M. anisopliae, and it was therefore classified as moderately toxic in this case.