Abstract: A compound needle for a knitting machine has a machine shank of substantially rectangular cross section, in which a substantially U-shaped longitudinal groove open at the top is formed. A closing slider adapted to fit the cross section of the groove is guided in the groove in a longitudinally slidable manner, and the groove has at least one slit leading to the outside, which extends parallel to the longitudinal axis of the groove.In order to attain satisfactory removal of fluff or lint from the longitudinal groove, on the one hand, and to assure sufficient stability and resistance to transverse bending of the needle on the other, the longitudinal groove is closed on its top, at least partially, in the vicinity of the recess by means of a rib which also forms a guide for the slider.