The present investigation reports light and electron microscopical aspects of the main olfactory epithelium (MOE) of the insectivorous bat Scotophilus heathi. Serial frontal sections of the nose and associated structures reveal: 1) that the MOE is located on most of the ethmoturbinals and on the proximal upper portion of the nasal septum; and 2) that the vomeronasal organ is absent in this species. The ultrastructure of the MOE of Scotophilus heathi is similar to that observed in other vertebrates. Moreover, we did not observe significant morphological differences between the MOE of male and female animals. Nevertheless, the supra-nuclear region of the supporting cells of males and females shows a different amount and distribution of "lysosome-like" cell organelles at the two times of the year investigated.