This paper introduces the laser transmission welding process as an advantageous joining technique and investigates its characteristics for welding thermoplastic polyurethanes (TPU). Laser power, feed rate, and clamping pressure are all variable parameters that influence the weld seam quality, and have been described and analyzed in detail in this paper. This process has been shown to be characterized by a wide processing parameter field and exhibits excellent monitoring and automation capability. Material strain property modifications were realized by adding endless glass fiber reinforcements in the welding area.