1. AbstractPurpose: This research paper provides an overview of the factors that influence customer loyalty; today it is known that customer loyalty is a key factor that can alter the customer's decision to repurchase a particular product/service. This research paper discusses relationship marketing, customer loyalty and customer satisfaction as key factors influencing customer loyalty. Design/Methodology/Approach: Data for this study was collected through a questionnaire distributed to the population of Islamabad and Rawalpindi. The results were obtained by testing the hypothesis with regression. Results: Limitations of the research: The limitation of this paper is that the data was collected only for the telecommunications industry. This research can be further conducted on the apparel and FMCG sector. Keywords: customer loyalty, customer loyalty, customer satisfaction and relationship marketing.2. INTRODUCTION Customer loyalty is a very ancient phenomenon, companies know that to generate more revenue they need to retain old customers, the beauty of retaining old customers was that they were loyal to the company (product, service) and would not think of change to some other product very easily, but however with the passage of time, the entry of competitors and the removal of barriers for global business there was a need to gain knowledge on how to retain customers. The Pareto model explains well that 80% of company revenues were generated thanks to 20% of loyal customers and their repurchase, thus demonstrating that it is much more difficult to acquire a new customer than to keep an old one. The purpose of this paper is to examine the different factors that influence customer loyalty. Customer loyalty is... at the heart of the paper... N. (2002), “The future of relationship marketing”, Journal of Services Marketing, vol. 16 No. 7, pp. 590-592. Smith, D.C., (1996), "The Do it all loyalty program and its impact on customer loyalty", Managing Service Quality, Vol. 6 No.5, pp. 33-37. Stauss, B., Chojnacki, K., Decker, A., Hoffman, F. (2001), “Retention effects of a customer club”, International Journal of Services, Vol. 12 No. 1, pp 7-19. Taylor, S.A., Celuch, K., Goodwin, S. (2004), “The importance of brand equity for customer loyalty”, Journal of Product & Brand Management, Vol. 13 No. 4, pp 217-227. Veloutsou, C., Scotland, G., Tzokas, N. (2002), “Relationship Marketing what if…?”, European Journal of Marketing, Vol. 36 No.4, pp. 433-449.Venetis, K.A. and Ghauri, P.N., (2004), “Service Quality and Customer Loyalty: Building Long-Term Relationships,” Vol. 38 n. 11/12, pp. 1577-1598.