This research discusses Electronic Government (e-Government), in particular the challenges that face its development and widespread adoption in Saudi Arabia. In this research e-government is defined as a matrix of stakeholders: Government to Government, Government to Business and Government to Citizens, using information and communications technology to deliver and/or consume services. Electronic Government has been implemented in developed countries for some time, while in Saudi Arabia it is still at the implementation and developing stages. Electronic Government services face challenges, including trust, privacy, security, computer and information literacy, and culture. In addition, this research has identified the influential factors, including quality of service, diffusion of innovation, knowledge and skills, culture, lack of awareness, technical infrastructure, website design, security, privacy, and trust, that affect the citizens' intentions to adopt e-Government services in Saudi Arabia. Therefore, these factors have been evaluated using an exploratory study, which uses mixed-methods, to confirm that these proposed factors are important and that the citizens are concerned about them. Resulting form the exploratory study, this research ha developed an integrated model for aiding the Saudi government by identifying the factors that would influence citizens to adopt their services. The model has been validated by the main study for this research, including questionnaires for citizens, government employees and experts. The gathered data were analysed and assessed using the Structural Equation Modelling approach. From the main study, the results showed that the proposed model fits the data and applies to the Saudi context. Therefore, the validated model would be considered essential in order to help the Saudi government to overcome the concerns of their citizens to use and adopt the online services. Consequently, applying the proposed model can reduce the government's time, effort, and money in influencing their citizens' intentions to adopt the proposed online services.