This paper undertakes a study on energetic and exergetic performance evaluation of various types of coals in Turkey, such as Armutcuk, Amasra, Zonguldak and Catalagzi hard coals and Tuncbilek, Beypazari, Cayirhan, Afsin, Soma, Yatagan, Can and Sorgun lignites for gasification purposes, where syn-gas may subsequently be used for the production of electricity, heat, hydrogen, etc. in industry. The chemical exergy contents of these coals are determined and compared for a potential use in gasification, and their energetic and exergetic efficiencies are also assessed for performance comparison. In the analysis, exergetic efficiencies are evaluated for an idealised gasifier in which chemical equilibrium is reached, ashes of coals are not considered and heat losses are neglected. It is observed that coals having lower heating value have higher gasification efficiency, and the ratios of hydrogen to chemical exergy of coal are related to the gasification process efficiencies of this coal.