Mergers and Acquisitions (M&As), despite being identified as risky, remain a strategy of choice for chief executives of organisations. Rates of failure have been reported to be as high as between 52 to 70% of M&As, failing to deliver their intended benefits and maintain shareholder value. These high failure rates are increasingly being blamed on organisational culture issues. Organisational culture, however, has been described as a rich but complex and confusing field with very different, albeit often overlapping, typologies (Wilson, 2005). This book argues theoretically from a functionalism view of culture and investigates empirically, methods of diagnosing and managing culture associated with successful M&As. The writer discovered that despite culture receiving a higher degree of visibility in recent times; it is still far from being a well-understood concept with a coherent methodology for diagnosing or managing it during M&As.