BackgroundChild mortality has become a prominent public health issue in sub-Saharan Africa (SSA). The mortality rates can in part be translated to how communities meet the health needs of children and address key household and environmental risk factors. Though discussions on the trends and magnitude of child mortality continue as to strategize for a lasting solution, large gap exists specifically in family characteristics associated with child death. Moreover, household dynamics of child mortality in SSA is under researched despite the fact that mortality rates remain high. This study aimed to examine the influence of household structure on child mortality in SSA.MethodsSecondary data from birth histories in recent Demographic and Health Survey (DHS) in 35 SSA countries were used in this study. The total sample data of children born in the 5 years prior to the surveys were 384,747 births between 2008 and 2017. Unadjusted and adjusted Cox proportional hazard regression model was fitted to model infant and under-five mortality. The measure of association was hazard ratio (HR) with 95% confidence interval (CI). Statistical test was conducted at p < 0.05 level of significance.ResultsTotal infant mortality rates were highest in Sierra Leone (92 deaths per 1000 live births), Chad (72 deaths per 1000 live births) and Nigeria (69 deaths per 1000 live births), respectively. Furthermore, total rates of under-five mortality across 35 SSA countries were highest in Cameroon (184 deaths per 1000 live births), Sierra Leone (156 deaths per 1000 live births) and Chad (133 deaths per 1000 live births). The risk of infant mortality was higher in households of polygyny, compared with households of monogyny (HR = 1.23; CI 1.16, 1.29). Households with large number of children (3–5 and ≥ 6) had higher risk of infant mortality, compared with those with 1–2 number of children. Infants from mothers with history of multiple union had 16% increase in the risk of infant mortality, compared with those from mothers from only one union (HR = 1.16; CI 1.09, 1.24). Furthermore, under-five from female household headship had 10% significant reduction in the risk of mortality, compared with those from male household headship (HR = 0.90; CI 0.84, 0.96). The risk of under-five mortality was higher in households of polygyny, compared with monogyny (HR = 1.33; CI 1.28, 1.38). Households with large number of children (3–5 and ≥ 6) had higher risk of under-five mortality, compared with those with 1–2 number of children ever born. Under-five from mothers with history of multiple union had 30% increase in the risk of mortality, compared with those from mothers from only one union (HR = 1.30; CI 1.24, 1.36).ConclusionHousehold structure significantly influences child mortality in SSA. Knowledge of drivers of infant and child death is crucial in health policy, programmes designs and implementation. Therefore, we suggest that policies to support strong healthy families are urgently needed to improve children’s survival.