Elevated levels of volatile organic compounds (VOCs) and particulate matters have been observed in recent years in Kocaeli, Turkey, despite improvements in pollution prevention technology that have led to a reduction in gas and particulate emissions. Local authorities should devise alternative strategies to reduce the possible health effects of a variety of pollutants that affect air quality. The objective of this study was to identify potential sources of VOCs, fine particulate matter (PM2.5) and coarse particulate matter (PM10) concentrations in atmospheric aerosols that were collected in the highly industrialised area of Kocaeli, Turkey, during the winter and summer months by using wind directions. Samples were collected from May 2006 to January 2007, and concentrations of eight elements (As, Cr, Cu, Mn, Ni, Pb, V and Zn) were measured using energy dispersive X-ray fluorescence (EDXRF) and wavelength dispersive X-ray fluorescence (WDXRF) spectrometer. Samples were analysed for thirteen VOCs, including benzene, toluene, m/p-xylene, o-xylene, ethylbenzene, styrene, cyclohexane, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, hexane, nonane and dodecane using thermal desorption (TD) and a gas chromatography/flame ionisation detector (GC/FID). The results show that vehicular emissions, oil and coal combustions, petroleum refinery and hazardous and medical waste incinerator are the significant sources of VOCs, PM2.5 and PM10 concentrations in Kocaeli.