Websites have evolved into an excellent medium of information dissemination and visibility. Hence governments and organizations around the world have websites as primary medium for information communication. The information in government web sites, which are widely adopted in many countries, must be accessible for all people, easy to use, accurate and secure. Since the web is an important resource of information for millions of people at all levels, accessible websites can help people with disabilities too to participate and contribute more actively in society. In recent years, many people have devoted their efforts to the issue of quality of Web site. The Quality and reliability of the e-government website is a crucial factor for the successful implementation of the information society. In this study the effectiveness of various design parameters (HTML errors, load time and browser compatibility problems etc.) on e-government website will be analysed by taking into considerations different website development standards recommended for them. The main objective of this study is to investigate the usability, accessibility and vulnerability of e-government web sites in Turkish Republic. Analysis was conducted using several automatic evaluation tools. The evaluation results show that the examined e-Government services have one or more accessibility issues. The results indicated that there is an urgent need to improve the design features of e-government website in order to be more effective and user-centric. The study also revealed security vulnerabilities in these web sites. Although the Turkish Ministry of Family and Social Policies as the framework for defining Web accessibility policy was launched at 2001, government web sites in the Turkish Republic have not been reviewed and still need great efforts to improve accessibility, usability and security. The author took 51 Government websites of Turkey, analyse their different parameters and on the basis of analysis shows their overall compliance with the standards and guidelines. With the help of the results obtained a table analysis of the websites is made by the authors that determine the effect of these parameters on the efficiency and accessibility of the government websites.