Background:Overweight/obesity (OW/OB) coexists in mother–child dyads. However, a dearth of evidence on the factors associated with this phenomenon calls for research.Objective:To analyze the association of sociodemographic factors with OW/OB in a sample of 260 Maya mother–child dyads from Yucatan, Mexico.Methods:During 2011 to 2014, we measured height and weight in children and their mothers and calculated their body mass index (BMI). The OW/OB cutoff points were defined, for mothers, as having a BMI >25 kg/m²and, for children, as having a BMI-for-age >2 standard deviation of the World Health Organization references. Mother–child dyads were grouped according to their BMI status: (1) normal weight mother and child, (2) normal weight mother and OW/OB child, (3) OW/OB mother and normal weight child, and (4) OW/OB mother and child. A multinomial logistic regression model was used to analyze the interrelationships among BMI status in mother–child dyads, household size, and parental education.Results:Overweight/obesity coexisted in 40% of dyads. Compared to normal weight dyads (1), each unit increase in household size and in years of maternal education decreased the risks of the coexistence of OW/OB in mother–child dyads (odds ratio [OR] = 0.72, 95% confidence interval [CI] 0.55-0.94, P = .015; OR = 0.70, 95% CI 0.52-0.94, P = .019, respectively). Conversely, each year increase in paternal education increased the risk for OW/OB in dyads (OR = 1.47, 95% CI 1.08-1.99, P = .015).Conclusions:Results suggest that household size and parental education contribute to shape BMI-based nutritional status in this sample of mother–child dyads.