This brief report details a study of the construct validity of the Internalizing Symptoms Scale for Children (ISSC) in comparison with the Child Self-Report Form of the Behavioral Assessment System for Children (BASC). Using self-reports of 121 students ages 8-12 from general education classes, who were administered both measures, correlational data were obtained between the scores of the two instruments. ISSC factor and total scores were found to have weak associations with the BASC School Adjustment Scales, and negatively associations with the BASC personal adjustment scales, providing discriminant evidence of the construct validity of the ISSC. Moderate to strong correlations were found between ISSC scores and the BASC Clinical Maladjustment, Other Problems, and Emotional Symptoms Index scores, evidencing convergent construct validity between the two measures. These results support the validity and clinical use of the ISSC as a measure of internalizing symptoms and emotional problems. (Contains 1 table.)