Microcerotermes Silvestri is a cosmopolitan genus and is distributed in all zoogeographical regions, except the Nearctic region. During the study of Iranian termite fauna, specimens of Microcerotermes were collected from Zabol (Eastern of Iran, Sistan). Morphological studies indicated that specimens belonged to a new species. In imagos, the head-capsule pale brown; postclypeus, labrum, antennae, pronotum and legs yellowish brown; tergites brown; intersegmental membrane pale yellow. In soldiers, the head-capsule yellowish brown, oval; anterior margin and around the antennal suture darker; antennae paler than the head-capsule; mandibles dark brown; legs and abdomen yellow. Microcertermes sistaniensis sp. n. comes closest to Microcerotermes diversus Silvestri, but can be separated from the lather on the basis of the morphological characters of the soldier and alate imago. In soldiers of M. sistaniensis, head oval, yellowish brown, the maximum width of head 1.12 mm, head length at mandible base to the maximum width of head (L/W) 1.23. In soldiers of M. diversus, head subrectangular, yellowish, the maximum width of head 0.90 mm, head length at mandible base to the maximum width of head (L/W) 1.55. In alate imagos of M. sistaniensis, the length of body without wings 6-7 mm, the length of head to the tip of labrum 1.19 mm and head width 1.07 mm. In alate imagos of M. diversus, the length of body without wings 4.5-5.2 mm, the length of head to the tip of labrum 0.91 mm and head width 0.78 mm.