A total of 128 spiny eels Mastacembelus mastacembelus (Mastacembelidae) were collected from theGreater Zab river at Iski Kalak town, west of Erbil city, Kurdistan region, Iraq, from July 2007 to the end ofJune 2008. The fish were examined for ecto and endo parasites. The study revealed the existence of 16species of parasites (with a total prevalence of 89.06%) including: two species of protozoans (Trypanosomasp. and Trichodina pediculus), one species of monogenetic trematodes (Mastacembelocleidusheteranchorus), six species of digenetic trematodes (Allocreadium transversale, Asymphylodoramacracetabulum, Pseudochetosoma salmonicola, Clinostomum complanatum, Diplostomum flexicaudum and D. spathaceum), two species of cestodes (Polyonchobothrium magnum and Ligula intestinalis), two species of nematodes (Agamospirura sp. and Procamallanus viviparus), one species of leech, crustacean and arachnoide (Cystobranchus mammillatus, Argulus foliaceus and Arrenurus sp. respectively). Five species of these parasites (T. pediculus, A. transversale, D. flexicaudum, C. mammillatus and Arrenurus sp.) wererecorded for the first time in Iraq. In addition, M. mastacembelus was regarded as a new host for A.macracetabulum, C. complanatum and A. foliaceus.