Olive cake (OC) is a by-product of olive oil production and is a solid material consisting of seed particles and the fleshy parts of olive. The Mediterranean region represents 98% of the world's olive tree population, and Turkey is among the top five main olive oil producer countries around the world. The main objective of the present study is to investigate the potential and utilization of olive cake ( OC) in the country. It is estimated that over 360,000 tons of OC, corresponding to an average of 150,000 tons of oil equivalent ( toe), were produced in the season of 2000-2001 in Turkey. From the combustion experiments performed in the conventional OC-fired boilers in the country, the values for CO-emissions were found to vary from 1,800 to 10,000 mg/m(3). Suitable combustion systems, such as fluidized bed systems, stoker fed from the bottom with secondary air supply, etc., should be used for efficient energy production from the OC. Determination of values of the flue gas can be used in calculating for heating surfaces.