Certain species of insects and mites induce galls to plant. The paper presents the results regarding on the presence of galls and gall insects and mites detected in period from 2010 to 2024 in urban greenery of Novi Sad city. A total of 28 species of insects and 10 species of mites causing gall on plants were found. The galls were encountered on the fruits, buds, leaves and branches. The gall insects belonged to Cynipidae, Aphididae, Cecidomyiidae, Tenthredinidae, Phylloxeridae, Psyllidae families and gall mites belonged to Eriophyidae family. The largest number of galls was found on the pedunculate oak, black polar and the white willow. Two non-native invasive species were identified as gall makers Obolodiplosis robiniae (Haldeman, 1847) on black locust and Dasineura gleditchiae (Osten Sacken, 1866) on honey locust. In addition to affecting the aesthetic appearance of plants, when the number of galls is high, their formation leads to the physiological weakening of plants.