Internet banking is one of the most important e-services in electronic commerce; however, the lack of standardised instrument for evaluating its satisfaction may inhibit the further development of Internet banking. This study aims to develop and validate a standardised measurement regarding customer satisfaction with Internet banking (IBCS). The development process included examinations of user satisfaction literature, expert panels, and pilot studies. Web survey was used for data collection, with subjects of Internet banking customers. The result was a parsimonious 18-item instrument with six subscales (content, accuracy, format, ease of use, timeliness, and safety) tapping into dimensions of IBCS. Further, this study not only affirms that all items in prior user satisfaction studies are still valid in the context of Internet banking, but also reveals that safety issues need to be addressed by banks to improve user satisfaction of Internet banking. Because of this rigorous and systematic study, researchers can use this valid measurement as a standardised instrument for measuring customer satisfaction of Internet banking.