Means to guide the back and forth motion of a pair of weft yarn grippers (1) along the shed of looms with continuous weft feed, of the type comprising two control straps (2) movable on a substantially horizontal plane thanks to the action of two gearwheels with reciprocating motion. Said straps (2) are provided with an undercut notch (3) on their lower surface, and they comprise a plurality of guide elements (4) apt to geometrically mate with said undercut notch (3), while the gripper (1), mounted at the end of the strap (2) on its upper surface, has its barycenter coinciding with or below the barycenter of the strap section.