Objective: To identify the association of household food insecurity (HFI) with anthropometric status, the risk of vitamin A deficiency and anaemia, morbidities such as cough and fever, and hospitalizations for diarrhoea and pneumonia in children under 5 years old. Design: Cross-sectional study using data from the 2006 Brazilian Demographic and Health Survey. HFI was measured with the Brazilian Food Insecurity Measurement Scale (EBIA). Vitamin A deficiency and anaemia were assessed in blood samples. Child morbidities were reported by the child's mother and included cough, fever, and hospitalizations for diarrhoea and pneumonia. Regression results were expressed as unadjusted and adjusted OR and corresponding 95 % CI for severe food insecurity, with statistical significance set at P < 0·05. Setting: Nationally representative survey. Subjects: Children (n 4064) under 5 years old. Results: There was no association between HFI and vitamin A deficiency, pneumonia, wasting or overweight. The prevalence of cough, fever, hospitalization for diarrhoea and stunting were associated with degree of HFI severity. There was a significant association of morbidities and stunting with severe food insecurity (v. food secure). After controlling for confounders, the association between severe food insecurity (v. food secure/rest of food insecurity categories) and the prevalence of common morbidities remained strong, showing that severely food-insecure children had a greater likelihood of experiencing cough (adjusted OR = 1·79) and of being hospitalized for diarrhoea (adjusted OR = 2·55). Conclusions: Severe HFI was associated with cough and severe diarrhoea among Brazilian children. Household food insecurity (HFI) happens when people do not have, at all times, physical, social and economic access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life (1) . HFI is a global epidemic that can lead to hunger and malnutrition. The FAO estimates that 795 million people are undernourished globally (2) . In Brazil, only 62·5 % of households are considered food secure and 4·8 % are severely food insecure, a percentage that reaches 5·8 % in households with minors under the age of 18 years (3) . HFI is known to be associated with insufficient or inadequate food intake (4) and this low intake of healthy foods and micronutrients is associated with worse health status (5) , both in developed and developing countries. Children are negatively affected by HFI (6,7) as it has been associated with a higher prevalence of hospitalization, respiratory infection, fever, diarrhoea, and nutritional deficiencies such as Fe deficiency and other forms of malnutrition compared with children living in food-secure households (8)(9)(10) . Food deprivation and poor dietary quality in childhood influence children's growth, psycho-emotional, social and cognitive development, and overall health (11,12) . According to the 2006 Brazilian Demographic and Health Survey (DHS), only 57 % of 12-to 18...