A series of carbons, prepared by nitric acid oxidation of an activated carbon and subsequent heat treatment at increasing temperatures to selectively reduce the oxygen surface groups, have been used to determine the enthalpy of immersion in liquids with different polarity (benzene, methanol, and water). The areal enthalpy of immersion for the carbon with low oxygen content follows the order benzene > methanol much greater than water, similar to that found for nonporous carbons. On the other hand, the presence of oxygen surface groups which evolve as CO2 upon heat treatment does not affect much the enthalpy of immersion in methanol or water, the groups evolving as CO being mainly responsible for the evolution of enthalpy of immersion. For nonpolar molecules such as benzene the enthalpy of immersion of the carbons is independent of the chemical nature of the carbon surface.