This study empirically investigates the relationship between maternal, prenatal and nutrition conditions versus infant mortality in Nigeria using monthly time series data spanning 2000–2025 obtained from the World Bank. The dependent variable was mortality rate, infant (per 1,000 live births) while cause of death, by communicable diseases and maternal, prenatal and nutrition conditions (% of total) served as the independent variable. A Vector Autoregression (VAR) model was employed to capture the relationship among the variables. VAR estimation results indicate strong persistence in infant mortality, as the lagged value of infant mortality (coefficient = 0.961428) exerted a positive and statistically significant effect on current infant mortality rates. Similarly, communicable diseases significantly explained their own future variations (coefficient = 0.918956), implying prolonged health shocks and persistence in disease prevalence. However, the cross-variable effects between communicable diseases and infant mortality were weak and statistically insignificant in the short run, suggesting that broader maternal and prenatal healthcare conditions may mediate the transmission mechanism. The model exhibited high explanatory power with stable dynamics, confirming the robustness of the estimated relationships. The study concludes that infant mortality in Nigeria is largely driven by persistent structural health conditions associated with inadequate maternal, prenatal and nutrition-related healthcare services. The study recommends increased investment in maternal and child healthcare, expansion of prenatal nutrition programs, improved immunization coverage, and strengthened public health interventions aimed at reducing communicable diseases and improving infant survival outcomes in Nigeria.