Understanding the determinants of malnutrition is pivotal for public health interventions. This study aimed to identify socio-economic, demographic, dietary, and maternal determinants of wasting and overweight among Brazilian children between 6–59 months. Data from the Brazilian National Survey on Child Nutrition were analyzed (n=11,789). Children’s weight-for height Z scores were calculated according to the WHO growth standard and classified as wasting (Z < -2), normal weight (-2 ≤ Z ≤1), overweight risk (1 < Z ≤ 2), and overweight (Z > 2). Socio-economic, demographic, dietary, and maternal covariables were considered. Adjusted multinomial logistic regression (odds ratio (OR) and 95% confidence interval (95% CI) was employed. The prevalence of overweight and wasting was 9.5% and 2.6%, respectively. In the adjusted model, younger age (6-23 months: OR: 1.7; 95%CI: 1.3; 2.2), consumption of ≥ 5 ultra-processed food groups (OR: 1.8; 95%CI: 1.1; 3.1), maternal underweight (OR: 0.4; 95%CI: 0.2; 0.9), overweight (OR: 1.5; 95%CI: 1.2; 1.9) and mild food insecurity (OR: 0.8; 95%CI: 0.6; 1.0) were associated with child overweight. The Brazilian Northeast (OR: 4.9; 95%CI: 2.1; 11.3), Southeast (OR: 7.1; 95%CI: 3.0; 16.6), South (OR: 4.7; 95%CI: 1.8; 12.1), Midwest regions (OR: 2.7; 95%CI: 1.2; 6.2) and maternal underweight (OR: 5.4; 95%CI: 2.7; 10.7) were associated with wasting. Overweight in Brazil is prevalent among children between 6-59 months, while wasting is not a major public health problem. The main determinants of these Brazilian children's nutritional status were age, ultra-processed food consumption, and maternal nutritional status.