Nowadays, the utilization of organizational knowledge and sharing it with other employees in governmental project-based organizations, have become a strategic source of gaining and preserving competitive advantage. Acquiring competitive advantage requires means and approaches that make the governmental project-based organizations capable of improving their knowledge sharing performance and gaining a better position. The initial goal of this paper is to comprehensively review the international literature on knowledge sharing and to present an applied model for measuring the knowledge sharing capability through the identification of the most approved and practical measurement indicators including human, organizational and technical factors. According to the statistical analysis and subsequent results, these factors are all influential on knowledge sharing in the governmental projects. Afterwards, the final approved model has been evaluated in one of the branches of the ministry of commerce as one of the most project-based governmental organizations. The statistical results have shown some weaknesses in the performance of knowledge sharing for which a comprehensive set of guidelines and recommendations have been provided. Finally, a set of guidelines for improving the knowledge sharing performance in project-based organization have been addressed and some suggestions for the future endeavors have also been provided for the interested audience.