Background <p>Ample research explores marital structures’ impact on children’s nutrition, yet results are mixed, and pathways remain underexplored. In this study, we examine the effect of marital structure on children’s nutritional status while estimating the mediation and moderation effects of household size and women’s empowerment, respectively.</p> Methods <p>We analyzed the latest Demographic and Health Survey data from 24 sub-Saharan African countries to evaluate the odds of stunting, anaemia, and underweight in children from polygynous households compared to those with single mothers and monogamous caregivers, using multinomial logit regression.</p> Results <p>Children from polygynous households were more likely to be anaemic, stunted, and underweight. Children of empowered monogynous mothers were associated with lower risks of malnutrition, whereas an increase in household size amplified childhood malnutrition in single and polygynous families. Wealth and sanitation also influenced childhood nutrition, with poorer households and those lacking proper sanitation experiencing worse nutritional outcomes.</p> Conclusion <p>This study underscores the complexity of the maternal structure and children’s outcomes and suggests interventions that seek to improve children’s nutrition status should factor mother’s empowerment and household size as key influencers.</p>