This study examines the relationship between corporate income tax, green investment, and ESG in Vietnam during the 2020–2025 period, drawing on a synthesis of domestic policy frameworks and international empirical evidence. The study focuses on whether tax incentives genuinely generate additional green investment or primarily reduce the tax liabilities associated with investments that firms would have undertaken anyway. The findings indicate that tax incentives can stimulate green investment by lowering after-tax costs and easing financial constraints; however, their effects are heterogeneous. Tax incentives may also give rise to non-additional investment, inefficient benefit allocation, and the risk of greenwashing. Against the backdrop of Vietnam’s ongoing efforts to refine its corporate income tax framework and green taxonomy, the study proposes a shift from incentives based predominantly on sectors or projects toward conditional, outcome-based incentives linked to additionality, measurable environmental outcomes, ESG transparency, and robust monitoring and clawback mechanisms. Accordingly, policy effectiveness should be assessed not merely by the amount of tax revenue forgone, but by the volume of additional green investment and the actual environmental outcomes generated per unit of foregone public revenue.

Dr. Luu Ngoc Tho, Dr. Chuc Kim Vinh, MSc. Chuc Kim Toan,"Corporate Income Tax and Green Investment in Vietnam: Do Tax Incentives Really Generate Additionality?" International Journal of Advanced Multidisciplinary Research and Educational Development, V2(5): Page(503-516) September - October 2026. ISSN: 3107-6513. www.ijamred.com. Published by Scientific and Academic Research Publishing.