The entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin and Beauveria bassiana (Balsamo) Vuillemin and the bethylid parasitoid Prorops nasuta Waterston are natural enemies of the coffee berry borer, Hypothenemus hampei (Ferrari), and are considered valuable biocontrol agents in the coffee-growing regions of Central and South America. Laboratory evaluations were made on the impact of three isolates of each fungus on adult P. nasuta. These isolates were selected because of their high virulence toward H. hampei in previous studies. B. bassiana isolate Bb25 and M. anisopliae isolate Ma4 caused the lowest infection levels in P. nasuta with LC₅₀ values of 8.31 × 10⁶ and 4.08 × 10⁶ spores per milliliter, respectively, by direct inoculation. Spore suspensions of each of these isolates were applied to coffee berry borer infested coffee berries. P. nasuta adult females were allowed to search and parasitize hosts within the treated berries. Despite the high virulence of these fungi to P. nasuta, neither pathogen significantly affected the predatory or parasitic capacity of P. nasuta, indicating that these isolates may be compatible with the action of the parasitoid under field conditions provided that pathogen applications and parasitoid liberations are timed not to coincide.