An understanding of the experience of food insecurity by children is essential for better measurement and assessment of its effect on children's nutritional, physical, and mental health. Our qualitative study explored children's perceptions of household food insecurity to identify these perceptions and to use them to establish components of children's food insecurity experience. Children (n = 32; 11-16 y old) from after school programs and a middle school in low-income areas participated in individual semistructured in-depth interviews. Children as young as 11 y could describe behaviors associated with food insecurity if they had experienced it directly or indirectly. Using the constant comparative method of qualitative data analysis, children's descriptions of behaviors associated with food insecurity were categorized into components of quantity of food, quality of food, psychological aspects, and social aspects described in the household food insecurity literature. Aspects of quantity included eating less than usual and eating more or eating fast when food was available. Aspects of quality included use of a few kinds of low-cost foods. Psychological aspects included worry/anxiety/sadness about the family food supply, feelings of having no choice in the foods eaten, shame/fear of being labeled as poor, and attempts to shield children. Social aspects of food insecurity centered on using social networks to acquire food or money and social exclusion. These results provide valuable information in understanding the effect of food insecurity on children's well-being especially relative to the social and emotional aspects of well-being.