In the rapidly developing world governments are thriving to become efficient and effective in the ways of delivering services to their citizens. Developing countries are funded by various bodies/developed countries to implement successful e-government projects to serve this need. However, in Sri Lanka most of the completed e-government systems are not being used by the end users, thus e-government projects’ sustainability is a major concern. In this research we analyse four e-government projects; two successes and two failures to derive factors affecting the sustainability of a project. It was identified that approach, method of deployment and user involvement are the critical success factors for e-government sustainability. We acknowledge that the approach should be bottom-up, method should be incremental and it is important to interact with all the stakeholders in each phase. With this we derive a framework for sustainability of e-government projects.