The aim of the study was to evaluate the microbial diversity of bacteria in soils long-term contaminated with crude oil. The samples were collected according to Polish Standard in July 2016 from the area of oil wells in Weglowka near Krosno (Podkarpackie voivodship, Poland). The samples were taken from the 0-20 cm layer in three replicates and sieved through a 2 mm sieve. The total content of petroleum hydrocarbons, PAHs level and the content of trace elements were determined.