In the course of experiments on the soils of construction sites in Irkutsk region and Irkutsk, the content of petroleum products was determined, and phytotesting was carried out on seedlings of seeds of higher plants. The experiments were conducted in a laboratory setting. An analysis of the soils of the construction sites of Irkutsk region and Irkutsk revealed the presence of petroleum products in the composition of polluting components, while their maximum concentration was recorded in the surface layer (0–10 cm). An assessment of soil phytotoxicity revealed a significant negative impact of pollution on plant growth, with inhibition of the root system and a decrease in capillary water capacity.