In 2010-2011, a study of the occurrence of aphids was carried out in three parks in Bydgoszcz, the Balaton Park, the Jan Kochanowski Park and the Park by Unii Lubelskiej. Observations were made every ten days by monitoring trees and shrubs as soon as aphids appeared, i.e. from the end of April to the beginning of August. The counts of aphids were replicated three times, on each plant species where the insects were observed. Based on the collected material, 14 aphid species were found on 16 plant species in the Jan Kochanowski Park, 16 species of aphids on 14 plant species in the Balaton Park and in the Park by Unii Lubelskiej, only 12 species feeding on 16 plant species. In both years of the study, of aphid species feeding on trees and shrubs, Aphis fabae, Aphis sambuci, Aphis spiraephaga and Hyalopterus pruni, occurred most frequently. The Balaton Park was characterized by the largest number of aphids colonizing plants; in contrast, the number of tree and bush species on which they fed was the lowest.