Iraqi refugees in Lebanon are vulnerable to food insecurity because of their limited rights and fragile livelihoods. The objective of the present study was to assess household food insecurity among Iraqi refugees living in Lebanon, almost 10 years after the invasion of Iraq. A representative survey of 800 UN High Commissioner for Refugees-registered refugee households in Lebanon was conducted using multi-stage cluster random sampling. We measured food insecurity using a modified US Department of Agriculture household food security module. We collected data on household demographic, socio-economic, health, housing and dietary diversity status and analysed these factors by food security status. Hb level was measured in a subset of children below 5 years of age (n 85). Weighted data were used in univariate and multivariate analyses. Among the Iraqi refugee households surveyed (n 630), 20·1% (95% CI 17·3, 23·2) were found to be food secure, 35·5% (95% CI 32·0, 39·2) moderately food insecure and 44·4% (95% CI 40·8, 48·1) severely food insecure. Severe food insecurity was associated with the respondent's good self-reported health (OR 0·3, 95% CI 0·2, 0·5), length of stay as a refugee (OR 1·1, 95% CI 1·0, 1·2), very poor housing quality (OR 3·3, 95% CI 1·6, 6·5) and the number of children in the household (OR 1·2, 95% CI 1·0, 1·4), and resulted in poor dietary diversity (P< 0·0001). Anaemia was found in 41% (95% CI 30·6, 51·9) of children below 5 years of age, but was not associated with food insecurity. High food insecurity, low diet quality and high prevalence of anaemia in Iraqi refugees living in Lebanon call for urgent programmes to address the food and health situation of this population with restricted rights.