Fertility pattern and reproductive behaviours affect infant death in Nigeria. Household food insecurity and poor care practices also place children at risk of morbidity and mortality. The objectives of this study were to assess the influence of family size, household food security status, and child care practices on the nutritional status of under-five children in Ile-Ife, Nigeria. The study employed a descriptive cross-sectional design. A semi-structured questionnaire was used to collect data from 423 mothers of under-five children and their children in the households selected through multistage sampling methods. Food-insecure households were five times more likely than secure households to have wasted children (crude OR = 5.707, 95 percent CI = 1.31-24.85). Children with less educated mothers were significantly more likely to be stunted. The prevalence of food insecurity among households in Ile-Ife was high. Households with food insecurity and less educated mothers were more likely to have malnourished children.