The experiments were carried out in 2008–2010 under field conditions in the north of the country (Bonin, near Koszalin). The influence of mineral oil (Sunspray 850 EC) and insecticide (Karate Zeon 050 CS, Pirimor 500 WG, Mospilan 20 SP) mixtures on the effectiveness in controlling aphids on potato plants was assessed. The largest aphid number was recorded in 2008 and in other years the number of aphids was very small. The dominant species was Aphis nasturtii Kalt. The highest effectiveness in controlling aphids populations on potato plants was revealed in case of the mixture of mineral oil with systemic insecticide Mospilan 20 SP and some good results were also obtained at a half lowered dose of the mixture.