There is disclosed a sewing machine having a needle bar gate vibrating mechanism whereby the sewing machine is adapted to produce zigzag stitches. The needle bar gate vibrating motion is obtained through the use of two spaced apart circular magnets mounted on a rotating shaft of the sewing machine and having disposed between them a pair of bar magnets operatively connected to the needle bar gate, the polarization of the magnets being such that one of the circular magnets exerts attractive force on the bar magnets while the other circular magnet exerts repulsive forces. As the shaft rotates these forces reverse, resulting in the imparting of vibratory motion to the needle bar gate.