AFRICA DEVELOPMENT AND RESOURCES RESEARCH INSTITUTE (ADRRI) JOURNAL ISSN: 2343-6662 ISSN-L: 2343-6662 VOL. 25, No. 3 (3), December, 2015 Published by Africa Development and Resources Research Institute 38 AFRICA DEVELOPMENT AND RESOURCES RESEARCH INSTITUTE (ADRRI) JOURNAL ADRRI JOURNALS (www.adrri.org) ISSN: 2343-6662 ISSN-L: 2343-6662 VOL. 25, No. 3 (3), December, 2015 Relationship Marketing; a Tool for Competitive Advantage in Banking Sector in Ghana. Emmanuel Kwarteng University of Education, Winneba, Kumasi Campus. Email: rabbikwart@yahoo.com Received: 16 th November, 2015 Revised: 19 th December, 2015 Published Online: 31 st December, 2015 URL: http://www.journals.adrri.org/ [To Cite this Article: Kwarteng, E., (2015). Relationship Marketing; a Tool for Competitive Advantage in Banking Sector in Ghana. ADRRI Journal, Ghana: Vol. 25, No. 3(3). Pp. 38-50, ISSN: 2026-5360, 31 ST December, 2015.] Abstract The study seeks to find out the significant relationship that exists between the sustainable long term relationship marketing and sustainable competitive advantage. By this, the study took a sample population of 341 respondents from the 11 commercial banks within the Sunyani Municipality and questionnaires were administered to them. 315questionnaires were returned to the researcher. However, 11 out of the 315 were not fully completed so they were excluded in the analysis. As competition has become very keen, relationship marketing has also become a very powerful tool for sustainable competitive advantage. The findings of the study revealed that there is a significant positive correlation between the practicing of relationship marketing and competitive advantage using spearman rank of correlation. Therefore, it is very indispensable for banks to include in their overall corporate business objectives and strategies that underpin the successful relationship marketing development as a tool for sustainable competitive advantage. Keywords: relationship marketing, transactional marketing, banking sector, customer loyalty, repeat purchases and customer retention.