A total of 250 wild sheep (Ovis orientalis) from different national parks and protected regions of Iran were examined for gastrointestinal nematodes at necropsy. Twenty five species of nematodes were found. Marshallagia marshalli, Ostertagia spp; Nematodirus spp; and Skrjabinema ovis were the most prevalent.

Although all the species found are recorded from wild sheep for the first time in Iran, 88% were reported previously from domestic sheep. New host and distribution records for Nematodirus davtiani, N. gazellae and Nematodirella longissimespiculata were established during the present study.