This paper examines the conceptual framework, institutional arrangements, operational challenges, and financing approaches of public investment management, with emphasis on its implications for economic growth, social equity, and institutional accountability. The study highlights that effective public investment management rests on five interrelated pillars: strategic planning, project appraisal and selection, implementation and procurement, operation and maintenance, and post-project evaluation. Key challenges include cost overruns, political interference, lumpy expenditure profiles, weak linkage between capital and recurrent budgets, and limited capacity at subnational levels. The paper further explores Public Investment Programmes, Public-Private Partnerships, and digital project management systems as strategies for bridging infrastructure gaps while maintaining fiscal discipline. It concludes that strengthening institutional capacity, enhancing stakeholder participation, and adopting rigorous appraisal methodologies are critical for improving the developmental impact of public investments.