IntroductionAs the largest profession within the healthcare industry, nursing and midwifery workforce (NMW) provides comprehensive healthcare to children and their families. This study quantified the independent role of NMW in reducing under‐5 mortality rate (U5MR) worldwide.DesignA retrospective, observational and correlational study to examine the independent role of NMW in protecting against U5MR.MethodsWithin 266 “countries”, the cross‐sectional correlations between NMW and U5MR were examined with scatter plots, Pearson's r, nonparametric, partial correlation and multiple regression. The affluence, education and urban advantages were considered as the potential competing factors for the NMW–U5MR relationship. The NMW–U5MR correlations in both developing and developed countries were explored and compared.ResultsBivariate correlations revealed that NMW negatively and significantly correlated to U5MR worldwide. When the contributing effects of economic affluence, urbanization and education were removed, the independent NMW role in reducing U5MR remained significant. NMW independently explained 9.36% U5MR variance. Multilinear regression selected NMW as a significant factor contributing an extra 3% of explanation to U5MR variance when NMW, affluence, education and urban advantage were incorporated as the predicting variables. NMW correlated with U5MR significantly more strongly in developing countries than in developed countries.ConclusionNMW, indexing nursing and midwifery service, was a significant factor for reducing U5MR worldwide. This beneficial effect explained 9.36% of U5MR variance which was independent of economic affluence, urbanization and education. The NMW may be a more significant risk factor for protecting children from dying under 5 years old in developing countries. As a strategic response to the advocacy of the United Nations to reduce child mortality, it is worthy for health authorities to consider a further extension of nurses and midwives' practice scope to enable communities to have more access to NMW healthcare services.