The Children’s Depression Inventory—Short Version (CDI–S), an abbreviated version of the widely used Children’s Depression Inventory (CDI), has been regularly used in recent research. In comparison to the original CDI, the CDI–S has not been rigorously evaluated for its psychometrics. The present study examined the dimensionality, convergent and discriminant validity, and gender differences of the CDI–S in a school-based sample of 809 children 8–12 years of age. All children completed the CDI–S. One subsample additionally completed another measure of depression, 1 subsample completed a measure of anxiety, and 1 subsample completed the CDI–S at a second occasion, after 2 weeks. Information regarding parents’ education and household income were available for 476 children. We evaluated the dimensionality of the CDI–S in a series of exploratory factor analyses. Despite some evidence of multidimensionality, a bifactor model revealed that the variation of scores was primarily explained by variations of the general factor. Consequently, the CDI–S is most adequately interpreted as a univocal measure. The CDI–S showed high correlation to another measure of depression and a moderately high correlation to a measure of anxiety, with nonoverlapping confidence intervals. We also found that girls reported higher levels of depressive symptoms than did boys, and we found a negative correlation between depressive symptoms and socioeconomic factors for boys only. Future studies should preferably include a broader age range, to acquire a more comprehensive understanding of the validity of the CDI–S.