ABSTRACT: OBJECTIVE:To examine associations between food insecurity, excess body weight, psychosocial factors and food behaviours among low-income African-American families. DESIGN:Cross-sectional survey of participants in the baseline evaluation of the B'More Healthy Communities for Kids (BHCK) obesity prevention trial. We collected data on socio-economic factors, food source destinations, acquiring food, preparation methods, psychosocial factors, beliefs and attitudes, participation in food assistance programmes, anthropometry and food security. We used principal component analysis to identify patterns of food source destinations and logistic regression to examine associations. SETTING:Fourteen low-income, predominantly African-American neighbourhoods in Baltimore City, MD, USA. SUBJECTS:Two hundred and ninety-eight adult caregiver-child (10-14 years old) dyads. RESULTS:Of households, 41·6 % had some level of food insecurity and 12·4 % experienced some level of hunger. Food-insecure participants with hunger were significantly more likely to be unemployed and to have lower incomes. We found high rates of excess body weight (overweight and obesity) among adults and children (82·8 % and 37·9 % among food insecure without hunger, 89·2 % and 45·9 % among food insecure with hunger, respectively), although there were no significant differences by food security status. Food source usage patterns, food acquisition, preparation, knowledge, self-efficacy and intentions did not differ by food security. Food security was associated with perceptions that healthy foods are affordable and convenient. Greater caregiver body satisfaction was associated with food insecurity and excess body weight. CONCLUSIONS:In this setting, obesity and food insecurity are major problems. For many food-insecure families, perceptions of healthy foods may serve as additional barriers to their purchase and consumption.