Paper presents a method of calculating the temperature distribution in cylinder for a 2-stroke, opposed-piston (OP) internal combustion engine (ICE). Development of such machines has been very limited after World War II due to technological and ecological problems [9], therefore progress in numerical modeling for analyzing highly boosted OP engines was also halted. Current technology permits returning to the OP arrangement, where due to better combustion chamber shape it is potentially possible to achieve higher thermodynamic efficiency than in arrangement with the cylinder head [9, 10]. Authors decided to use a general purpose CFD-program (in this case Ansys Fluent) coupled with additional tools to calculate conjugated heat transfer between the load in the cylinder and the cylinder itself to get a 3D temperature distribution in solid body.