Success of mergers and acquisitions today largely gets influenced by HR functions. If we analyze the reasons for failure of mergers and acquisitions, two major issues that we observe in most of the cases are problems with culture integration and people integration. There are other problems like poor business integration, synergy, etc. But these problems are addressed well before the deal for mergers and acquisitions is finalized. Although it is possible to guard against culture and people integration issues through HR due diligence, HR problems may still continue till businesses of two organizations get fully integrated. Thus a thorough understanding of HR functions in relation to mergers and acquisitions is required.