This study assessed the effect of adult male and female mortality on economic growth in Nigeria. The objectives are to identify the determinant of adult mortality in Nigeria; investigate the disaggregated effect of adult male mortality and adult female mortality on economic growth in Nigeria. Descriptive analysis with Secondary data on the Nigerian economy from 1982 to 2023 and the Auto Regressive Distributed Lag technique was used to carry out the study. We found that the determinants of adult mortality in Nigeria include Income per capita; Government Spending on Health; Insurgency; Agricultural output; Education and Labour Force Participation Rate. Our results show that men and women mortality have a negative and significant effect on economic growth both in the short and long run, but the effect of men’s mortality is higher than that of the women. We recommend increased public and private funding of the education of the girl child, especially in the northern part of Nigeria, restructuring and strengthening of the armed forces and increased government spending on health.