Abstract: The invention relates to a method for monitoring a lateral offset of an actual weld seam configuration relative to a desired weld seam configuration, in particular in the motor vehicle sector, comprising the following steps: a) providing at least a first structural part having a geometric deviation in the region of the desired weld seam configuration; b) guiding a laser beam along the first structural part to produce a weld seam, forming a melt pool, thereby producing the actual weld seam configuration; and c) detecting a reflection from the melt pool simultaneously with step b).