This study determines the effects of service quality dimensions on customer satisfaction in Pakistan by using SERVQUAL model. A survey research questionnaire of 30 items has been adopted and collects the data of 400 respondents from the users of internet banking of different bank located in Karachi city of Pakistan. Reliability analysis shows that all dimensions are reliable. Results of factor analysis confirm the grouping of adopted questioner. At last, regression analysis indicates significant positive relationship between assurance, tangibility, reliability and responsiveness with customer satisfaction. Conversely, empathy shows positive but insignificant effect on customer satisfaction. It is recommended that the management of online banks has to focus on making the design and content of the websites more visually appealing to grab the attention of existing customers, as well as to attract new customers. The management has to take effective measures to further enhance the security and safety of online bank accounts, so that customers can maintain long-term relationships with the usage of online banking. Online banks have to provide more reliable services to the customers at heart to make the customers more comfortable and confident. The management should develop more effective systems to solve the issues of customers quickly.