Common bean (Phaseolus vulgaris L.) is the important vegetable of very short vegetation, during which it must be protected from pests. It is one of the most important vegetables for direct consumption in the world. As well as the other culture plants it is susceptible to pest attack, the most important of which are aphids (Aphidae), two-spotted spider mite (Tetranichus urticae C. L. Koch), beetle (Bruchus pisorioum L.), thrips (Thysanoptera), some species from Heteroptera suborder, and insects from Muscidae and Cicadidae family. Aqueous extract of stinging nettle (Urtica dioica L. and Urtica urens L.) is a significant bio-insecticide. A field research was carried out within the VIP project „Aqueous extract of stinging nettle- myth or reality“. There were eight beds and two repetitions with different treatments for the purpose of protecting plants from pests. The number of pests was recorded according to the modified method of Liu (2004.). The number of aphids, thrips, and leaf-miners was recorded during the research. The number of aphids on beds ranged from 19,44% to 40,27%, and it is found that the best effect on pest control has the long aqueous extract of stinging nettle. Presence of thrips on the beds ranged from 26,36% to 47,22%. In two repetitions on the equally treated beds was found the biggest and the smallest number of the thrips. The number of leaf-miners ranged from 1,39% to 3,47%, and due to the small number of pests, efficiency of aqueous extract cannot be established. From the study, it is apparent that the nettle has a positive effect on the number of aphids, but it is necessary to repeat the research to make more relevant results.