The objective of this research is to present a method to bioassay entomopathogenic Bacillus species against sand fly (Diptera, Psychodidae, Phlebotominae) larvae. The vector Lutzomyia iongipaipis (Lutz & Neiva, 1912) (Diptera, Psychodidae, Phlebotominae) and some Bacillus strains were used in laboratory to develop this method. Some characteristics of this method are commented and the importance to develop a standard method to test pathogenicity of Bacillus species against phlebolomine larvae is also discussed.