Abstract: In an internal combustion engine having at least two working pistons, each reciprocating in one cylinder and acting on a crankshaft through one connecting rod each and with at least one balance piston movably mounted in a balance cylinder of its own for balancing the inertial forces, the balance piston is driven by the crankshaft through a balance connecting rod, the crank of the balance piston being disposed between the cranks of the two working pistons. The cylinders of the working pistons are disposed in a “V” arrangement and the axes of the cylinders of the working pistons are positioned at an angle of 0°<&agr;<45° to one another, the axis of the balance cylinder being arranged in a first center plane including the crankshaft axis between the two cylinders of the working pistons.