The amount of solid waste produced in Istanbul, the biggest city in Turkey with a population of 10,072,447 according to the 2000 census, is about 9,000 tons per day. The amount of organic substances is more than 45% and leads to the formation of high amounts of flammable and explosive solid waste gases accumulated in Istanbul land-fill sites. Because of their flammable and explosive properties, it is very important to monitor the level of emissions of these gases to ensure regulatory requirements are met. In this study the gas emission measurements of methane (CH4), acetylene (C2H2), oxygen (O-2), carbon monoxide (CO), and hydrogen sulfide (H2S) are carried out in Kemer-burgaz-Odayeri solid waste landfill site, Istanbul. The emission average values measured were as follows: 5.2-37 vol% for methane, 71.6 - 100% LEL (Lower Explosion Limit; 100% LEL= 2.3vol%) for acetylene, 2.7-20.9 vol% for oxygen, 9.6-145.8 ppm for carbon monoxide, and 22.6-95 ppm for hydrogen sulfide. Methane and acetylene concentrations were in the explosively flammable range at landfill gas vents. Also, carbon monoxide and hydrogen sulfide concentrations were remarkably high at the vents. The emission values of these landfill gases were compared with Turkey's criteria and international legal criteria.