The results of experiments showed an effect of magnetized water on the effectiveness of some selected zoocides. The control of red spider mite (Tetranychus urticae Koch) by Ortus 05 SC showed the highest effectiveness with strongly magnetized water, with use of one magnetizer and two semi-rings. On the other hand, the application of Magus 200 SC in combination with magnetized water showed a decreased effectiveness of insecticide. In the control of grain weevil (Sitophilus granarius L.), an increase in the effectiveness was found for the zoocides Talstar 100 EC, Karate 025 EC and Winylofos 550 EC in combinations with strongly magnetized water (three magnetizers or one magnetizer with two rings). In case of Sumi-Alpha 050 EC, high effectiveness of the treatment was obtained in combinations where water was magnetized in lesser degree, with use of one or two magnetizers. No significant differences were found in the effect of magnetized water on germination of bean (Phaseolus vulgaris L.) and cuckoo flower (Cardamine amara L.) plants.