Rats are capable to harbor various pathogens, among which certain species of zoonotic parasites are included. A long-term detection of parasite fauna of rats has sporadically been carried out in Iran. Abundance of these vertebrate pests is of great importance as regards public health issue. The present paper is fo­cused on a digenean trematode Plagiorchis muris, obtained during a comprehensive study on rats over the decades in the country. Herein we describe this occurrence in a Rattus norvegicus in northern Tehran, with specific note on its morphological description. P. muris can infect human through consumption of infected marine food items, and has never been observed in Iran.