In Summary, the overall purpose of this dissertation is to evaluate whether or not Relationship Marketing creates competitive advantage and retention value for Grameen Phone, the leading telecom company in Bangladesh.Also, the investigation also pursues to reach other sub objectives, which would enable to answer efficiently the major question which has just cited above. According to the objectives, a successful assessment of framework has been created from the leading academics which are the literature review. A core role of this thesis is played by the Literature Review (Chapter-3) with the starting point of presenting the ancient origins, and fundamental terms of Relationship Marketing. This is followed by the paradigm shifting from traditional marketing to relationship marketing and the inherent benefits to all the parties involved in this process which is at the heart of the marketing discipline. Then it moves more broadly consider the RM practice in detail greatly emphasizing on customer retention to create competitive advantage.A conceptual framework adopted from Literature Review has been conducted to discover Relationship Marketing success in a graphical demonstration.