A machine for kneading dough portions into a round shape is provided with a kneading drum adapted to be driven in the peripheral direction and in the direction of an axis. The kneading drum is concentrically enclosed by a compartmented drum adapted to be rotatingly driven in a peripheral direction and has kneading chambers open radially outwardly and radially inwardly towards the kneading drum. Furthermore, the compartmented drum has, looped around a portion of its periphery, in a belt contact zone, a kneading belt which presses the dough portions against the kneading drum and prevents them from falling out of the kneading chambers.The kneading belt can be driven by a positive drive which is independent of bearing forces between the kneading belt and the surface of the compartmented drum, whereby the kneading belt no substantial bearing forces on the belt contact zone of the compartmented drum.