BackgroundLife expectancy at birth (LE0) is one of the most widely used indicators for determining the overall development of a country. Worldwide, LE0has increased over the last ten years in most countries. This parameter is essential for developing countries as they strive to achieve socio-economic progress by investing significantly in social sectors like social services and safety nets. LE0among West African countries has consistently been the lowest in African regions, which calls for more research. This study aimed to quantify LE0losses and gains by sex in West African countries from 1990 to 2021. We hypothesize that lower life expectancy rates in the West African countries were likely due to poorer socioeconomic indicators than in other African regions.MethodsLife tables by sex and country were calculated for sixteen (16) West African countries from 1990 to 2021. LE0for 1990, 2000, 2010, and 2020 were contextualized alongside recent trends between the two sexes and country. We used decomposition techniques to examine which sex and country contributed to gains and losses in LE0between 1990 and 2021. RStudio software was used to calculate differences in LE0from one year to another. In addition, linear regression, life disparity, and the Gini coefficient were used to trace the evolution of LE0in the last three decades in West Africa.ResultsThere were LE0gains from 1990 to 2021 in all sixteen West African countries (Benin, Burkina Faso, Cape Verde, Ivory Coast, Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo). The highest LE0gains between 1990 and 2021 were observed in Guinea-Bissau among males (28.32 years), followed by females in Niger (20.41 years), followed by males in Mauritania (18.91 years), and females in Liberia (18.13 years). The least LE0gains were observed in males in Mali (4.48 years). Most West African countries achieved the highest LE in 2019 (14/16, 75.0%), except for Cape Verde in 2017 (5.28), and Togo in 2021 (0.94).ConclusionAlthough most West African countries posted progressive LE0gains from 1990 to 2021, there were LE0losses in 2020 and 2021 when the COVID-19 pandemic emerged. The West African region has the lowest LE0of all African regions probably due to lower socio-economic indicators compared to all other African regions. Also, during the COVID-19 pandemic in 2020 and 2021, there were LE0losses in all West African countries, except Togo. In addition, LE0gaps between males and females were highest in the late 1990s and least during the late 2000s. Even though several studies reported that morbidity and mortality rates of COVID-19 were lower in Africa than in the rest of the world, a more comprehensive study is warranted to assess the actual impact of COVID-19 on West African countries.