The term ‘microplastics’ is defined as a category of pollutants that are highly prevalent in aquatic environments and have the potential to exert adverse consequences on biological systems. In this study, the presence and diversity of microplastics in the muscle, liver and digestive systems of the fish species Barbus anatolicus, Cyprinus carpio and Capoeta tinca, collected from the River Kızılırmak (Nevşehir), were examined in detail. This waterway flows through densely populated areas and empties into the Black Sea. Eighty‐two microplastics were identified in the muscle tissue of the fish, 74 in the liver and 208 in the digestive system. The majority of these microplastics were white and fibre‐shaped. The microplastics detected were of various plastic types, including polyamide, polypropylene, nylon, polyethylene and polyester. The findings of this study demonstrate the significant impact of human activity on the environment, with the presence of microplastics in aquatic ecosystems and living tissues.