This book explores the relationships between Company Income Tax (CIT), Institutional Quality (IQ), and the Tax Effort Ratio (TER) and their collective impact on the economic growth of 15 West African countries from 2000 to 2022. It aims to understand how CIT influences economic growth and the moderating role of IQ. CIT, a key source of public revenue, and IQ, which shapes a nation's economic outcomes through its institutions, together with TER, measure taxation relative to economic capacity and provide insights into revenue effectiveness. Using a dynamic panel ARDL model, the study finds that CIT, IQ, inflation, and exchange rates negatively affect GDP, while trade openness positively influences growth. Institutional quality and trade openness further boost growth, while the MG model shows negative impacts of GDP and IQ on TER, with inflation and foreign direct investment having positive effects. The study provides critical recommendations for improving tax policies, institutional reforms, and attracting foreign investments to support sustainable growth.