The invention relates to a double-sided, indexable turning insert having a polygonal basic shape, comprising a plurality of corners, a peripheral clearance surface, and identical upper and under sides, in which there are included support surfaces situated in a reference plane, which are parallel to each other and to a neutral plane, which is situated halfway between the reference plane and toward which the clearance surface extends at a right angle. Along the upper side as well as the under side, primary cutting edges are present, which individually include a nose edge situated in a corner and two main edges, which converge toward the same and are located in a nose plane inclined in relation to the neutral plane, and which transform into auxiliary cutting edges, which run parallel to the neutral plane and separate each pair of primary cutting edges along one and the same side of the turning insert, chip-directing guide surfaces being placed inside the chip surfaces of the cutting edges. According to the invention, the primary cutting edge has a generally positive cutting geometry so far that a wedge angle of the cutting edge between the chip surface and the clearance surface is acute in arbitrary sections along the nose edge as well as along the two main edges. In such a way, the primary cutting edge becomes easy-cutting and produces chips that can be guided in a careful, although distinct way by the guide surfaces being inside.