Six species of terrestrial isopods from the province of Qazvin, central Iran, are recorded. Three species, Hemilepistus
klugii (Brandt, 1833), Protracheoniscus
ehsani Kashani, 2014 and Mongoloniscus
persicus Kashani, 2014, were previously reported from the province. Hemilepistus
elongatus Budde-Lund, 1885 and Protracheoniscus
major (Dollfus, 1903) are recorded for the first time, and one species, Protracheoniscus
sarii
sp. n., is described as new. The diagnostic characters of the new species are figured.