Laser cutting has become a promising alternative to conventional machining of carbon fibre reinforced plastics (CFRP). Advantages are a high automation potential, flexibility in use and non-contact operation. During the laser cutting process, the thermal energy input can cause modification to the cut edges, known as heat affected zone (HAZ). To make the process applicable in industry, knowledge about the spread of HAZ is essential. To reduce testing effort, a macroscopic simulation model is developed to simulate the temperature expansion over time, depending on the process strategy. In this study, a unidirectional CFRP with an epoxy resin is used. Several parameters influence the quality of the cut, including the angle between the cutting direction and the fiber orientation, the scanning velocity, frequency, and the intervals between multiple laser scan repetitions, when employing a multipass cutting strategy. Since the carbon fibres have a much higher thermal conductivity compared to the matrix of the composite, the fibre orientation has a strong influence on the resulting temperature field. Thermography imaging of the process is used to detect surface temperatures on both sides of the material. The measured temperatures serve to validate the simulation model and they are correlated with the spread of the HAZ, which is analysed in cross-sections.