The main goal of the article is to determine project's success factors and instruments allowing to reach a success while conducting a project. First, the issue of project's success criteria is investigated. Till now project's success was measured of if the project didn't exceed budget, if it was finished on time and met all quality requirements. However Iron triangle axiom is hesitated. It asserted that it is not able to provide reliable data about importance of stakeholder's influence and meeting all their needs. From the point of projects' success criteria, a question arises what should be identified as project's successthe project itself, project management or projects' product success? Another important part of this paper represents the factors which may lead to successful finish of projects. Even though in scholar literature there can be found a lot of success factors, there is no systematic view of it. Some authors suggest that success factors are strongly related to project manager, team, environment and organization. While others affirm that view to success should be through project life cycle stages. In both cases scholars submit information based on practical researches. At the end, after theoretical research, the paper represents structural view to project success factorsstrongly defined parameters by which it can be ascertained if the project reached any success, and also it is recommended to use success factors to finish project as successful. The type of the article: Theoretical article.