This study assessed the impact of external debt on longevity in developing countries, particularly in West Africa, from 1981 to 2020. Longevity was proxied by life expectancy at birth, while the external debt effect was evaluated from the perspective of sustainability, liquidity, and solvency. Furthermore, outcomes from macroeconomic volatility were controlled through inflation and exchange rate variability. Methodological robustness was ensured by adopting panel unit root, cointegration, and estimation procedures incorporating panel dataset cross-sectional dependency and heterogeneity in their estimation process. Robust inferences for the study were derived by comparing estimated outcomes from the cross-sectional augmented autoregressive distributed lag, dynamic common correlated Effects, and the Driscoll-Kraay method. Empirically, the study showed that unsustainable, illiquid, and insolvent external debt and macroeconomic volatility shorten longevity in West African countries. Hence, longevity will decline when weak external debt management promotes poverty in West Africa and other developing countries.