We analyzed seasonal changes in Tawny Owl (Strix aluco) diet in a broadleaved forest in Eastern Ukraine over 6 years (2007-2012). Annual seasons were divided as follows: December-mid-April, April-June, July-early October, and late October-November. In total, 1648 pellets were analyzed. The most important prey was the bank vole (Myodes glareolus) (41.9%), but the yellow-necked mouse (Apodemus flavicollis) (17.8%) dominated in some seasons. According to trapping results, the bank vole was the most abundant rodent species in the study region. The most diverse diet was in late spring and early summer. Small forest mammals constituted the dominant group in all seasons, but in spring and summer their share fell due to the inclusion of birds and the common spadefoot (Pelobates fuscus). Diet was similar in late autumn, before the establishment of snow cover, and in winter. The relative representation of species associated with open spaces increased in winter, especially in years with deep snow cover, which may indicate seasonal changes in the hunting habitats of the Tawny Owl.