A composite needle, particularly for rectilinear knitting machines, comprising a needle body (2) that forms a hook-like portion (3) at one end and a slider (4) that can slidingly engage the needle body (2), the needle body (2) having, in a central portion, an I-shaped transverse cross-section that forms two slots (10, 11) that slidingly accommodate laminas (12, 13) forming the slider (4). The needle body (2), proximate to the end that forms the hook-like portion (3), has elements (27) for divaricating the laminas (12, 13) in the extracted position with respect to the needle body (2).