The study examined the screening effectiveness of the Children's Emotional Adjustment Scale (CEAS), a parent-reported scale that measures the emotional competence of children across four continuous factors (temper control, mood repair, anxiety control, social assertiveness) anchored in adaptive child behaviors, characteristics and skills that are vital to healthy social-emotional development and adjustment of children. Mothers of 1071 school students aged 6-12 years reported on their children's emotional functioning on the CEAS. In addition, mothers answered the Strengths and Difficulties Questionnaire, as well as the generalized anxiety disorder and major depressive disorder subscales of the Revised Child Anxiety and Depression Scale--Parent Version, which served as indicators of mental health problems to be targeted in the analysis. Area under the curve estimates ranged from 0.56 to 0.94, and sensitivity and specificity rates were 0.59-0.93, and 0.55-0.83, respectively. Temper control evidenced the greatest accuracy relative to overall mental health problems, externalizing problem and depression problems. Mood repair was most accurate in detecting overall mental health problems, internalizing problems and depression problems. Anxiety control was most efficient in detecting anxiety problems and internalizing problems. Social assertiveness was most sensitive in identifying internalizing problems. The findings suggest that the CEAS may be of value in early population-based screening. The instrument provides developmentally appropriate and actionable information on the emotional competence of all mainstream children on broad factors underlying both healthy and unhealthy social-emotional development, which can inform preventive interventions and treatment of common mental health problems in school-aged children.