Soil is an essential renewable resource that man depends on for existence. The number of vehicles on the roads is increasing at an alarming rate and have resulted to increased exhaust emissions (gaseous and particulate), fuel leakage, damping and wear and tear of vehicle parts which in turn have caused air and soil pollution along major roads. This Book aims at assessing the concentration of heavy metals Pb, Zn, Cu, and Ni in soils along busy roads in Nairobi using the Energy Dispersive X-Ray Fluorescence Spectrometer (EDXRF). The book gives a detailed procedure of soil sampling, soil preparation, calibration and optimization of the EDXRF and EDXRF data analysis. The results obtained show that the levels of heavy metals in most of the sampling sites along heavy traffic roads in Nairobi were above the average concentration values of elements on the earth crust. Though vehicles no longer use leaded fuel, the research show a general tendency of heavy metal Pb, Zn and Cu concentrations reducing with increasing perpendicular distance from the road and depth. Heavy metals when ingested or inhaled cause adverse health effects on man hence the need to minimize exposure to heavy metals.