The objective of the research is to identify the quality of banking services as an input to improve the marketing performance of the banks in Gaza governorates from the perspective of their customers. The researcher used the descriptive analytical method, and the research community consisted of customers at Bank (Palestine Limited, Islamic Palestine, Housing, Jerusalem, Arab Bank). The study tool was a questionnaire applied to a simple random sample of customers. A total of (141) responses were recovered with a recovery rate is equal to (78%). The results of the study showed that the level of availability of the banking service quality dimensions (safety, credibility, efficiency of service providers, tact, empathy, reliability, communication, accessibility, material and human aspects, response level) in banks operating in the Gaza Strip was high from the point of view of customers. The results showed that the level of marketing performance of banks operating in the Gaza Strip from the point of view of customers was high. The results also confirmed a statistically significant relationship at the level of (α≤0.05) between the quality of banking service and marketing performance in the banks operating in the Gaza Strip from the point of view of customers. The main recommendations were: To monitor and follow up the feedback in the banking market, which includes measuring customer perceptions about the mix of services provided, their acceptance and satisfaction, and identifying the positive and negative aspects to be used. The need to work on developing a marketing information department that includes information about customers and their level of income and their social and economic status, their needs, and desires, as well as the adoption of a marketing intelligence system on the behavior of competitors and their activities until the launch of new innovative services. Work to open channels of communication between the departments of banks and customers to keep banking institutions more flexible and responsive to the aspirations of customers towards the overall banking services provided, which contributes to improve marketing performance. The need to create an appropriate banking environment for the Bank's customers to make positive use of the global financial transformations, thus contributing to the efficiency of its performance. The need to use modern marketing methods and trends in dealing with customers, which require taking their views into account to develop banking services to enhance marketing performance. The need to encourage banks to researchers and those interested in banking services to carry out applied studies and scientific research in this area, by providing them with the financial support and data required to do so.