Subterranean termites are one of the most important pests of buildings, historic monuments and agricultural crops in some parts of Iran. Using entomopathogenic fungi as microbial insecticides is usually a part of biological control and insect pest management. The pathogenicity of entomopathogenic fungus, Metarhizium anisopliae (Metschnikoff) Sorokin (DEMI 001) isolated from Rhynchophorus ferrugineus (Oliver) was compared against two subterranean termites, Amitermes vilis (Hagen) and Microcerotermes gabrielis (Weidner) under laboratory conditions. Suspensions of the fungus spores at five concentrations of 101, 102, 103, 104, 106 spores ml-1 were prepared to define LC50 and LT50. To determine LC50 and LT50 of M. anisopliae, bioassays were carried out on worker casts of both termite species. LC50 values for A. vilis and M. gabrielis were 8.5 × 103 and 0.2 × 102 spores ml-1, respectively. LT50 value for M. gabrielis was shorter than that of A. vilis at all five concentrations tested. According to the results of the bioassay, M. anisopliae was more effective for controlling M. gabrielis than that for A. vilis.