In a two-needle sewing machine for making an ornamental stitch without a cover stitch, at least one intermediate lug (17) is provided which is disposed in side by side relation with respect to an upper thread take-up (13) engaged to the needle bar (7), said intermediate lug, in the absence of a workpiece (4) on the needle plate (8), is brought to a work position in which it interferes with one of the needle threads (4a, 4b) coming from an auxiliary thread take-up (12) being part of a feed unit for the needle threads. In the presence of the intermediate lug (17) in the work position, the orientation of the needle thread (4a) intercepted by said intermediate lug is suitably deviated with respect to the upper thread take-up (13), so as to cause a tension release on the needle thread itself during the raising steps of the needles (3a, 3) towards the upper dead center of their reciprocating motion.