The invention provides a method for a friction stir welding process, which comprises the steps of conventional stir welding—including applying friction to the areas of the workpiece to be welded by means of a rotating tool (20) that has a large shoulder that is pressed downwards on the workpiece and has a probe inserted into the material to be welded. The tool being advanced along the weld line. The method additionally comprises generating a laser beam (28) and collimating and focusing said beam on the workpiece in the weld region (29) ahead of the rotating tool. The invention also provides an apparatus for friction stir welding, which comprises the elements of conventional stir welding apparatus—including a rotating tool (20) that has a large shoulder and has a probe for insertion into the material to be welded, a mechanism for holding the tool and rotating and advancing it, a mechanism for pressing the tool shoulder downwards on the workpiece, and a mechanism for clamping the workpieces. The apparatus further comprises a laser beam generator (25), a laser beam conduit (26), preferably consisting of optical fibers, and collimator (28) and focusing optics for focusing the laser beam on the desired area of the workpiece.