Customer satisfaction is an important dimension for performance measurement for any organization. Customer satisfaction plays a key role in the banking sector as it is important for the development of a good relationship with customers which eventually affects the financial performance of banks. There has always been a challenge in identifying the criteria that should be used for customer satisfaction measurement, service quality in banks depends a lot on the employee professionalism especially for employees of customer service departments of banks. Moreover, excellent service quality is vital for business profitability and survival in banking sector. This research recommends measures that can be used to measure client satisfaction and evaluates its impact on the financial performance of banks in two types of private banks in Egypt, conventional banks and Islamic banks through studying a sample of bank clients in one of each type. This study shows customer satisfaction as a predictor of bank profitability. The purpose of this paper is to identify the main financial and non-financial aspects or factors that lead to customer satisfaction in banking services and then to determine to what extent customer satisfaction affects the banks' profitability. Moreover, the research also investigates whether there is a difference in customer satisfaction factors in conventional banking from Islamic banking.