Project Management in Guinea is growing rapidly such as in many developing countries. It’s heavily used now in diverse area such as in agriculture, construction, manufacturing, telecoms, IT, education, and so on. This high prevalence of making projects in various sectors determined the increasing importance of effective project management. Managing project rightly at a right time with multiple constraints (human and technical aspect) remains the main challenge for project managers. The relationship concerning successful project and the project success factors are topics of great interest in project management. The paper highlights the most Critical Success Factors (CSFs) through project planning, project top management support and stakeholder involvement in project implementation in Guinea.