The aim of this study was to analyze the prevalence of mental health disorders in children living in residential care and their use of therapeutic services, including the relationship between these factors and social-family and intervention process variables, as well as the relationship among the disorders identified by professionals and the detection of disorders by means of a screening instrument. We studied a sample from the Autonomous Community of Extremadura in Spain made up of 264 children ages 6 to 18 years. Data collected from residential care workers on the children’s characteristics and the existence of disorders and possible treatments were used, as well as the Child Behavioral Checklist as a screening instrument. In addition, the case social workers provided information on social-family and intervention process variables. Results show that 26% of the children in residential care were receiving or had received treatment for mental health disorders. Seventeen percent of the total presented mental disability, and in half of these cases, they were also being treated for mental disorder. The screening test, however, detected that cases with clinical range accounted for 44% of the children and that there was considerable bias in relation to referrals for treatment.