Superior structural capabilities and lightweight of carbon-fibre-reinforced polymer composites have made their applications increasingly noticeable particularly in the aerospace and automotive industries for reduced fuel consumption. Anisotropic and heterogeneous features of these materials, however, have been prohibiting the application of laser cutting on these materials in industrial scale. In the present study the thermal degradation characteristics in laser cutting of these materials are investigated with a nano-second pulsed diode pumped solid state Nd:YAG. A statistical analysis was performed for the optimisation of the process parameters. Furthermore, quality improvement was achieved by the use of low oxygen content assistant gas simultaneously with the inert gas shield. The controlled presence of oxygen as a burning mechanism reduced the fibre pull out up to 55% at the same time with a high processing rate.