Project managers from different areas struggle to find universal set of factors to achieve high project efficiency. However, the project efficiency assessment varies across industries, making it difficult to apply general concepts and guidelines in the specific project environment. The study’s main purpose is to assess the impact of organizational support on project efficiency in different areas and identify critical processes that increase it. The paper presents quantitative research results by using data from 261 project managers in the Republic of Kazakhstan during 2018–2019. The research sample consists of commercialization projects, scientific projects, social projects, and projects from the service industry. The research findings show the different quality levels of top management support and its high correlation with project efficiency. Furthermore, the study reveals the specific processes for each investigated type of project that highly correlate with project efficiency dimensions. Commercialization projects that intensively use the organizational support processes were the most efficient projects by showing the best result in cost overrun (15%) and the second resulted in schedule overrun (17%). These findings have theoretical and practical implications, supporting project managers in increasing their project efficiency by choosing the critical, proper project management tools and techniques.