The research work conducted for this thesis is intended to test two hypotheses formulated to test the failure of acquisition of two pharmaceutical giants: H1: Success or failure of mergers and acquisitions is determined by extent of due diligence given by acquiring company before signing the deal; H2: Strategic drivers are the determining factors of success of mergers and acquisitions. Research was designed to follow deductive theory and positivism theory to achieve the objective of the study based upon empirical data. Data was collected using review of annual reports, review of corporate governance reports and by questionnaires from the employees of new entity. Analysis of the data was done by using simple and standard statistics. Simple numbers and percentage was used for simple statistics and standard deviation and correlation analysis was done by using standard statistics.I studied M.Sc. - Microbiology in India and MBA - International Management in Germany. My 10 years of international pharmaceutical experience has helped me writing this book. In this publication I have explored the significant role of those factors that remain hidden during, but conclude the success or failure of Mergers and Acquisitions later.