Abstract Children are consuming less healthy foods, and this eating behaviour exposes the child to greater Na intake. The association between family, maternal and child characteristics with Na intake by children aged 13–35 months was evaluated. A study carried out with retrospective data on 1,185 children from the Brisa cohort. The children’s dietary Na intake was assessed by a 24-h diet recall survey. Values ≥ 1200 mg were considered excessive intake. The association between Na intake and independent variables was assessed by a three-level logistic hierarchical regression model. Variables with P-value < 0·05 were retained in the model. Most children were male (51·2 %), eutrophic (63·2 %) and not exclusively breast-feeding (EBF) for 6 months (58·4 %). The average Na intake was 925 mg (±410·4). The prevalence of excessive Na intake was 18·5 % and was associated with the variables children of younger mothers (< 20 years old OR = 4·04, 95 % CI 1·64, 9·99; ≥ 20 to < 35 years old OR = 2·48, 95 % CI 1·10, 5·63), having four or more children (OR = 2·51, 95 % CI 1·29, 4·89), lower family income (≥ 1 and < 3 minimum wages OR = 0·60, 95 % CI 0·39, 0·93; ≥ 3 minimum wages OR = 0·50, 95 % CI 0·30, 0·82) and not being EBF until 6 months (OR = 1·64, 95 % CI 1·14, 2·34). The average Na intake of children was higher than the recommendation for adequate intake, pointing to a high consumption of this micronutrient in the first years of life. Excessive Na intake seems to be linked to unfavourable socio-economic conditions. Avoiding early weaning is the only possible intervention in this scenario.