The telecommunications sector in Saudi Arabia is continuously seeking to a close relationship with their customers. Most telecom companies have Customer Relationship Management (CRM) system. However, implementing CRM systems have a low success rate. This paper aims to propose a model that helps the telecom companies to increase the level of implementing successful CRM system. A model is drawn to identify the critical success factors that contribute to successful CRM system in Saudi telecommunication sector. Seven basic hypotheses were tested, as parts of a theoretical model of successful CRM system. Data was collected through a questionnaire. The empirical analysis was carried out using a structural equation model and regression. In addition, follow-up interviews were conducted with a small number of top managers. Data obtained from the questionnaire was triangulated with data gathered from follow-up interviews. The findings revealed that the seven hypotheses were supported and lead to CRM success.