Chlorophenoxyacetic herbicides such as 4-chloro-2-methylphenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetic acid (2,4-D) are used for cereal protection. However, some of them penetrate the tissues of protected plants and also get in contact with cereal pathogens. The up-to-date studies concerned their effectiveness in combating the weeds without paying attention to the herbivores occurring in cereal agrocenoses. Therefore, the aim of the present study was to determine the effect of chlorophenoxyacetic herbicides on the probing behavior of grain aphid, Sitobion avenae (F.), bird cherry-oat aphid, Rhopalosiphum padi (L.) and rose-grain aphid, Metopolophium dirhodum (Walk.). The experiment was carried out on wingless females feeding on winter wheat seedlings of Tonacja cv. using the electronic penetration graph (EPG) method. Tested herbicide preparations exerted an influence on the probing behavior of all aphids examined. The inhibitory effect of MCPA and 2,4-D on the uptake of phloem juice was found. It has been shown that chlorophenoxyacetic herbicides are not only effective in combating the weeds of cereal crops, but can also have positive side-effects in the form of limiting the cereal aphids population.