Laser transmission welding (LTW) of thermoplastics is gaining increasingly importance as an alternative welding process in comparison to the conventional processes (like heated tool welding, friction welding or induction welding) due to its advantages as high flexibility, low mechanical loads, weldability of complex geometries, high welding velocities and precise energy deposition. Nevertheless, process limitations like attainable weld strength and gap bridging are competing parallel with the conventional welding processes. The influence of the key process parameters and their interdependence is still not completely illustrated. Though, this is a condition for the optimisation of the weld joint. In order to enhance the quality of the weld seam, laser beam guiding strategies for contour welding are studied. These strategies are mainly based on the method of the laser beam oscillation. For this, a laser beam is guided at high frequency and short amplitude relative to the main laser weld direction (weld contour). In this study, results of weld seam quality by using different strategies of laser beam guiding during contour welding will be shown.