Mergers & Acquisitions are a very complex topic and they are very often mentioned in the daily news. In order to accomplish the integration successfully many factors have to be considered. A rather rarely used approach is to combine Mergers & Acquisitions and knowledge based business process management. The purpose of this paper is to check if knowledge based business process management can be a key success factor in the post-merger integration phase. Furthermore this paper investigates the role of employees in an M&A transaction. A literature research was performed to gain an overview of theoretical findings in these two subjects. Additionally, a series of nine interviews was performed as a qualitative method of research. The data was analyzed based on a qualitative content analysis by Mayring. The results of this research provides the insight, that knowledge based organisation concepts are very little used in Austrias IT sector. Nevertheless, a lot of tools from knowledge based business process management are supplement for a post-merger integration. During post-merger phase process analysis can be used to gain insight in the targets business processes. In addition to existing integration controlling tools key performance indicators, the PDCA-cycle by Demin, risk management and changemanagement can be used for a smooth integration. Finally, based on the maturity level of the merging companies knowledge base, business process management can bring an advantage for M&A activity. Certainly, it can provide access to a faster integration and various synergies.