Coal and gas outbursts can be defined as a sudden release of coal and rock accompanied by large quantities of gas into the working face or other mine workings. It has been a major geological hazard to underground coal mining for over 150 years, and continues to cause serious problems all over the world. The outburst events have appeared rarely in metal mines and have generally occurred in salt and coal mines especially bituminous coal mines. Coal outbursts have occurred in at least 18 nations including Turkey. The most important factors that influence the occurrence of outbursts are gassiness of the coal seam and the desorption rate of the gas in the seam and or part of the coal seam. It is necessary to investigate these factors separately to predict the outburst prone zones. The aim of this study is to determine the outburst prone zones in the Zonguldak Coal Basin. In order to determine the outburst proneness of the coal seams, coal samples were taken from Kozlu and Karadon Collieries. 19 coal samples were taken from underground working areas, from 7 different coal seams, at different depths and with variable borehole lengths. Gas content of the coal seams was measured with US Bureau of Mines (USBM) Direct Method. Desorption rate of the gas in coal was investigated and a threshold limit determined for the study area. According to the experimental results, the coal seams have been classified with regard to outburst prone zones.