Laser welding is a very important factor in modern industrial production. Especially in automotive industry, it can gain advantages to fulfil the current demands in lightweight design and meet high productivity together. But laser welding is also a highly sophisticated process. To reach good welding results, a lot of different influences have to be considered. In this regard, process monitoring plays a major role. Almost every modern in-process monitoring approach is based on electromagnetic techniques. All investigations of acoustic emissions were concentrating on lower frequency ranges (< 100 kHz air-borne; < 500 kHz structure-born). In order to set up a welding process with new parameters, metallography is applied offline to measure all important quality parameters of the laser welds.