Insects’ antennae are important sensory structures as inferred from sexual and interspecfic differences in form and as demonstrated by electrophysiology. We conducted scanning electron microscopy (SEM) studies of the antennae of male and female Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae), an ectoparasitoid of several stored-product insects. The antennae of pteromalids are divided into scape with radicula, pedicel and flagellum. The flagellum is further divided into anelli, funicle and clava. Excised antennae of P. cerealella which had been reared under laboratory conditions were mounted on stubs, air-dried, sputter coated with gold (2.5nm) and viewed at 10Kv with a digital SEM (Zeiss, West Germany). SEM revealed basiconic, coeloconic, placoidea and hair-like trichoid sensilla to be present on the antennae of the parasitoid. Fewer sensilla were found on the ventral surface of the proximal antennal segments. Tricoid sensilla are alternately distributed all over the antennal segments but they occur in clusters on the basal, radicula segments. Significant differences were observed in the distribution and morphology of sensilla on the antennae of male and female P. cerealellae .