The paper presents the results of the research of 16 polycyclic aromatic hydrocarbons (PAHs) associated with four fractions of particulate matter (PM, PM₁₀, PM_2,5 and PM₁; fractions of particles whose aerodynamic diameter ranges from 30 nm to respectively: 100, 10, 2.5 and 1 µm) conducted at points located on the side of a highway and at a busy crossroads in Katowice. The highway research was carried out in the spring, and the crossroads research in the summer of 2012. Samples were taken by low pressure impactor DEKATI. The analysis of PAHs in ambient particulate matter samples was performed by gas chromatography. The average concentration of the sum of 16 PAH associated with PM, which amounted to 14.6 ng/m³ in the spring, was two times higher than in the summer. This concentration was a few or even several times lower than the levels recorded earlier in the cities of southern Poland in the winter. Meanwhile, indicators of toxicity, mutagenicity and carcinogenicity calculated for PAH at the highway and the crossroads were high. This indicates high health risk generated by the presence of PAHs in the Katowice air also in spring and summer time. The values of diagnostic ratio, roughly showing the origin of PAHs associated with the PM, confirmed that during the period of the research transportation was the main source of PAHs in both points of Katowice.