Collisions between birds and aircraft have resulted in loss of human lives and aircraft. We evaluate the efficacy of a falconer’s activity at deterring birds from Dęblin Military Airfield in Eastern Poland. The activity of a falconer using trained raptors (goshawk Accipiter gentilis, saker Falco cherrug, and peregrine Falco peregrinus) resulted in a reduction in the total number of birds in the airfield, in comparison with the control period. The greatest reduction in the number of birds in the airfield under influence of the trained raptors’ action was recorded for: European starlings, black-headed gulls, and rooks. We found a significant negative correlation of total bird numbers with the number of days after the beginning of the falconer’s activity. The significant trends in reduction of the number of birds observed at the airfield was indicated for many studied species, including: domestic pigeons, lapwings, and jackdaws. The effectiveness of the falconer in deterring birds was greater in the spring-summer period, in comparison with the autumn-winter period. Drawbacks of the falconry programs are discussed.