The urgent need for in-depth analyses of the patterns and determinants of food and nutrition insecurity in urban areas in Uganda cannot be overemphasized. Using cross-sectional data, this study explores the key determinants of the food security and child nutrition status among poor households in Kampala. First, raising the incomes of the urban poor may turn out to be an effective means of reducing the food insecurity problem and child malnutrition. Second, while maternal education has a stronger impact on girls’ long-term nutrition, paternal education has a stronger impact on that of boys. Conversely, increases in income tend to have a bigger effect on girls’ current nutrition compared to that of boys. All in all, efforts to fight poverty per se may not improve the food security and nutrition status of the urban poor; other factors need to be considered.