Mergers and acquisitions remain a popular means of corporate growth but the role played by organizational culture remains poorly understood. Badly executed cultural integration is a leading cause of post-merger performance not meeting stakeholder expectations (Cartwright&Schoenberg, 2006). This paper reviews the literature on cultural integration in the context of mergers and acquisitions and provides insight into cultural assessment and integration.The study takes the form of exploratory research with findings from twelve semi-structured interviews collated and tested against five propositions that together build a reference point for cultural integration. Five cultural assessment tools are incorporated into a single view to provide the reader with a clear framework against which to assess organizational culture.The study validates the proposition that cultural integration plays a key role in post-merger performance and provides key elements towards a successful integration. The study goes on to find that cultural integration is necessary for post-merger performance, an integration plan should be built early in the pre-merger process, top management has an integral role to play in the post-merger integration of culture, large cultural differences can be an opportunity and that the level of learning and knowledge application in mergers and acquisitions is poor.