The invention relates to a balancing shaft, whose balancing weight is located between two cylindrical bearing surfaces and which is configured as one piece with said weight. The end cross-sections of the balancing weight are circular segments that are delimited by an arc and a secant. The aim of the invention is to configure the balancing shaft in such a way that the mass effect and rigidity are optimal. To achieve this, the contours of the balancing weight on the plane that is fixed by the secants of the two end cross-sections taper from the two end cross-sections towards the longitudinal centre and the contours on the normal plane form a straight line in relation to said plane.