Abstract Upon collection and inspection of some fish specimens, belonging to seven species, from the lower reaches of Diyala river, mid Iraq, two ciliated protozoans (Chilodonella cyprini and Trichodina domerguei). two sporozoans (Myxobolus oviformis and M. pfeifferi ), three trematodes (Dactylogyrus vastator, Ascocotyle coleostoma and Diplostomum sp.), one nematode (Contracaecum sp.), one acanthocephalan (Neoechinorhynchus agilis), one crustacean (Ergasilus sieboldi) and one fungal species (Saprolegnia sp.) were detected. The mugilid fish Liza abu and the stinging catfish Heteropneustes fossilis represent new host records for C. cyprini and D. vastator, respectively, in Iraq.