Previous research reports a significant prevalence of child depression worldwide and self-concept as a predictor of depression and suicide behavior. Although suicide in children is an increasing problem in Mexico, there are scarce studies reporting risk factors and none of children in foster care institutions. This was a comparative, ex post facto study whose aim was to analyze associations between suicidal ideation, depression, and self-concept in two paired samples of Mexican children (83 institutionalized and 83 noninstitutionalized). Results show 16% of the children reported suicidal ideation and statistically significant differences among variables in both samples. Suggestions are made to address this problem from early ages.