The Grameenphone (GP) is a market leader in the telecommunication industry in Bangladesh. This study investigates thernexisting and expected service quality of Grameenphone users in Bangladesh. The Study reveals that there are significant gap betweenrnexisting and expected perceived service network, 3G, customer care, physical facilities, billing cost, information service, mobile banking andrnGP offers. The study concludes that customer satisfaction is a dynamic phenomenon. Maintaining desired level of customer satisfactionrnrequires corporate proactive responsiveness in accessing, building & retaining satisfied customers for sustainable competitive advantages inrnthe marketplace.