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. (PsycINFO Database Record