Precipitation hardenable aluminum alloys are some of the most important lightweight materials. However, their range of applications in comparison to conventional deep drawing steels is limited by the low formability. Therefore, a new and innovative approach to enhance the formability of aluminum alloys in multistage forming operations was invented at the Institute of Manufacturing Technology, called intermediate heat treatment (IHT). Based on a short-term, laser-assisted heat treatment between two forming steps, it is possible to locally adapt the mechanical properties and realize an optimized strength distribution. For the successful application of the technology, the influence of the heat treatment on the mechanical properties has to be analyzed. Concerning the simulation of a multistage forming process, in particular, the yield surface of the material is very important. Within this paper, the influence of a combined pre-straining and a subsequent short-term, laser-assisted heat treatment on the yield surface will be presented.