Abstract: A needle assembly for use in a knitting machine, particularly circular and flat knitting machines having one or more working systems and one or two working needle beds, the needle comprising a casing body of elongated rectangular form with a groove in its upper two-thirds portion, the head of the needle forming a hook for picking up the thread and the body having a cross-section of elongated U-shape at the groove. In the interior of the groove there is slidably arranged a plate likewise of rectangular and elongated form and provided with a lug projecting laterally from the body of the needle. The needle is provided at its lower portion with a lug for co-operation in the course of its passage on the cams of the working system of the machine during its needle raising and lowering action, the plate likewise co-operating by its lug with positioning stops of the working system of the machine in respect of the opening and closing, as necessary, of the hook of the needle.