The investigations were conducted to determine the effect of mineral fertilization and liming on selected soil properties and activity of entomopathogenic nematodes and fungi. Liming applied in three subsequent years of investigations did not cause any significant changes in soil reaction or hydrolytic acidity value in individual treatments. In comparison with organic carbon content determined in a soil sample collected prior to the experiment outset a considerable increase in this component soil concentration was found (mainly in the 0-10 cm layer), which points to ac-cumulation of organic matter in the soil of the experimental treatment. On the basis of obtained results a lesser content of mobile forms of lead, copper and cadmium were found (in the 0-10 cm layer) on the fertilized objects. NPK and Mikrovit treatment, against the background of liming, favoured better nematode activity in trap insect infesting. A greater activity of entomopathogenic fungi was registered in the topsoil, while mineral fertilization did not affect entomopathogenic nematodes and fungi pathogenicity. The applied fertilization may lead to weaker reproduction of nematodes, the symptoms of which were already observed on the basis of the obtained results.