The morphology of the metathoracic scent glands of Coreus marginatus (Linnaeus, 1758) (Heteroptera: Coreidae) was studied by scanning electron microscopy. The metathoracic scent glands are composed of a reservoir and a pair of lateral glands that connect to the reservoir through a duct. The metathoracic scent glands open to the surface through paired ostioles located between the 2nd and 3rd coxae in evaporation areas with a mushroom-like structure. Extracts of the volatile fraction from male and female metathoracic gland secretions were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Thirteen and sixteen compounds were detected in males and females, respectively. Most of the chemical compounds are qualitatively similar on each male and female but they differ in their quantity. In the analyses of metathoracic scent glands of females of C. marginatus, n-hexenoic acid (22.46%) was determined at the most and 14-Beta-H-Pregna (0.12%) was determined at the least in all samples. In males, octadecanoic acid (57.78%) was determined at the most and n-hexyl acetate (0.06%) was determined at the least in all samples.