The number of families sheltered in the Paris region (France) increased by a factor of 5 between 1999 and 2009. In 2013, a survey was performed on homeless families in order to characterize their living conditions, their health needs and the developmental problems in children. This random survey was conducted in 17 languages among homeless families sheltered in emergency centers for asylum-seekers, emergency housing centers, social rehabilitation centers and social hotels in the Paris region. The situation was particularly worrying regarding their food security. Indeed, only 14.0% of people were with food security, whereas 43.3% were with low food security and 9.8% very low food security (a situation where children are also affected). Stratified multivariate robust Poisson models showed that some characteristics can lead homeless families to be at higher risk of food insecurity and/or at higher risk of falling into very low food security, such as residential instability, single parenthood, having more than 3 children, depressive symptoms, housing in social hostels, difficult access to cheap or free food locally. These harmful situations are intolerable in such a wealthy region as the Paris region. They argue for a better detection of these families, a closer social follow-up and an increase in food aid.