Despite the rapid growth in technology and the research effort given on investigating the adoption of electronic banking services, both banks and academic researchers in developing countries perceive the problem of low-level adoption of electronic banking. Most studies which have investigated the adoption, acceptance, or intention to use electronic banking, have agreed that customers «trust is one of the most important impediments that have frustrated the success of the adoption process. Therefore, in developed countries, customers» trust became the pivot of research studies that investigated the electronic dealings between customers and new IT/IS innovations. Recently, a few researchers have started investigating online trust in developing countries. Although electronic banking services have been widely adopted in developed countries, there is still low usage in developing countries such as Saudi Arabia. This quantitative research aims to empirically determine the significant antecedents of electronic Banking Service Adoption, as well as to explain how the Diffusion of Innovation Theory (DOIT) is being used in determining the antecedent of electronic banking in Saudi Arabia. Using an adopted survey instrument, (5-point-Likert scale) is used. Were eventually used to further analyse the data using mainly The Partial Least Square (PLS). This study contribute to the body of knowledge by extending existing literature to identifying the factors influencing the acceptance of electronic banking among banks customers, developing a comprehensive model which contributes to online customer literature by extending the Diffusion of Innovation Theory (DOIT) to include trust and system reliability applying them to the context of electronic banking, extending existing literature by applying the developed model to Saudi customers, contributing to technology acceptance theories by showing the role of system reliability in the acceptance of electronic banking, Contributing to the electronic trust literature by examining the role of customer trust in the context of electronic banking and how it might be increased.