The diet of the barn owl Tyto alba was studied at the Kızılırmak Delta (Northern Turkey) between May 2014 and May 2015. A total of 436 pellets were analysed and 1118 prey remains (mammals, birds, amphibians and insects) were encountered. Participation of animal species in the diet was assessed on the basis of their frequency (F%) and biomass (B%). Nine mammal taxa (3 of Eulipotyphla, 1 of Chiroptera and 5 of Rodentia) were found in the diet composition. Mammals (F= 96.8%, B= 95.65%) were more frequent in the diet content than other groups (F=< 4%, B=< 5%). White-toothed shrews Crocidura spp. were the most frequent prey (annual F= 64%, B= 34.9%). Voles Microtus spp.(F= 18.3%, B= 28.76%) were more abundant in summer. Rats Rattus spp. were only found in autumn (F= 0.5%, B= 6.03%) and winter (F= 0.5%, B= 4.59%). The distribution of preys in the content of the barn owl diet did not vary seasonally (p> 0.05). Both prey diversity and evenness were low.