A rotation switching device for a sewing machine having a lock stitching mechanism and an overlock stitching mechanism. The device includes a rotatable operating member and a base disc connected to the operating member and movable in a vertical direction upon rotation of the operating member between a rest position in which the base disc is above the machine mounting surface and an operating position in which the base disc projects downward farther than the feet on the lower face of the machine body. In this position the base disc contacts the machine mounting surface to lift the body of the sewing machine from the mounting surface, whereby the body of the sewing machine may be rotated in a horizontal plane to place either the lock stitching mechanism or the overlock stitching mechanism to a use position.