In the contemporary business milieu and "era of customer", delivering quality service is a sine qua non in ongoing strategy of most business firms and constitutes integral ingredient for success and survival in present day´s competitive environment. This study investigates the role that service quality plays in the Ghanaian banking sector and its impact on service delivery. A sample of 400 customers encompasses four major indigenous and foreign banks. SERVQUAL dimensions of service quality were used to structure the questionnaire. William L. Boyd, Myron Leonard, and Charles White's Standard Instrument for weighting of rating of service quality attributes was the sampling procedure adopted. Data collected was analyzed using one sample T-test of the mean weighted differences between perception and expectation of customers. This, in an attempt to determine whether there is a significant gap between expectation and perception at 5% level of significance. Empirical findings from this study show that gaps exist between customers' expectations and perceptions of service delivery in all the banks even though the banks performed better on the tangibility dimension. Despite this observation, the banks retained their customers. This study, therefore, concludes that where a gap exists between customer expectation and perception of service delivery, service quality is perceived as low and customer dissatisfaction results. However, dissatisfied customers did not necessarily defect. The study therefore confirms the theory that service quality is a necessary but not a sufficient condition for maintaining strong relationship with customers.