Many children's food products highlight positive attributes on their front-of-package labels in the form of nutrient claims. This cross-sectional study investigated all retailed packaged foods (n 5620) in a major Brazilian supermarket, in order to identify the availability of products targeted at children, and to compare the nutritional content of products with and without nutrient claims on labels. Data on energy, carbohydrate, protein, fibre, Na and total and SFA content, along with the presence and type of nutrient claims, were obtained in-store from labels of all products. Products targeted at children were identified, divided into eight food groups and compared for their nutritional content per 100 g/ml and the presence of nutrient claims using the Mann-Whitney U test (P < 0·05). Of the 535 food products targeted at children (9·5 % of all products), 270 (50·5 %) displayed nutrient claims on their labels. Children's products with nutrient claims had either a similar or worse nutritional content than their counterparts without nutrient claims. The major differences among groups were found in Group 8 (e.g. sauces and ready meals), in which children's products bearing nutrient claims had higher energy, carbohydrate, Na and total and SFA content per 100 g/ml than products without nutrient claims (P < 0·05). This suggests that, to prevent misleading parents who are seeking healthier products for their children, the regulation on the use of nutrient claims should be revised, so that only products with appropriate nutrient profiles are allowed to display them.Key words: Labelling: Food products: Packages: Children: Nutrition Brazil, similar to most developing countries, has experienced an increasing trend towards purchasing and consuming processed food products (1) , as well as rising rates of overweight, obesity and other non-communicable diseases. The increase in obesity in the country has followed the classical demographic spread from adults to adolescents and then to children (2) . In 2013, 56·9 % of Brazilian adults were overweight and about 20·8 % were obese (3) . From 1974 to 2009, the prevalence of overweight in children (6-11 years) significantly increased among both males (8·3-33·8 %) and females (7·2-30·0 %) (2) , whereas obesity rates among children (5-9 years) reached 15·0 % (4) . Brazilian overweight and obesity rates are higher than global averages, ranking fifth among all countries in terms of number of obese people (5) . It has been estimated that by 2050 the healthcare costs attributable to obesity and overweight-related diseases in Brazil will double from $5·8 billion to $10·1 billion, and that nearly 70 % of Brazilian adults could be overweight if the present trends are sustained (6)