Caddisfly sampling conducted during August 2021 from the Gurgur River in the Sabalan Mountains, Ardabil province, Iran, revealed the first record of Glossosoma unguiculatum Martynov, 1925 for Iran. Previously, this species had only been known from few localities in Turkey, the Caucasus and Kazakhstan. The morphology of male genitalia in the collected specimens generally corresponds to the described species, with the exception of a less incised ventral margin of the abdominal segment IX in ventral view, which may be attributed to geographical variability. This discovery marks the second species of the genus Glossosoma Curtis, 1834 found in Iran.
