The trophic spectrum of an Asio otus colony from Chişinău city in winter period of 2011-2013 was studied. There were collected about 1000 pellets, of which almost 400 were analysed. The main prey species of long-eared owl are the small rodents, which constitute more than 95% from all identified animals, the birds, shrews and bats were recorded in low quantity. The main prey of Asio otus individuals were the species of genus Microtus (M. arvalis and M. rossiameridionalis), which constituted almost 55%, followed by Apodemus sylvaticus and by ther species of genus Mus (M. spicilegus and M. musculus). Other species registered less than 5%. Thus, the trophic spectrum of long-eared owl in winter period consist mostly of field vole, which is the most abundant in agroecosystems and is considered pest species.