This article presents two studies evaluating the construct validity and reliability of the “Young's Early Maladaptive Schema Questionnaire-Short Version” (YSQ-S3; Young, 2005). The first study, with 1004 participants, showed that the YSQ-S3 had excellent overall reliability according (Cronbach’s α=.97; ω=.97); while the factors showed acceptable to good reliability according to the range in which the minimum and maximum reliability coefficients of the 18 scales were placed (α from.67 to.89, and ω from.67 to.86). Confirmatory factor analysis (CFA) showed that the model with 18 first-order correlated factors had the best fit indices. In addition, using CFA with second-order factors, evidence was found to support the hierarchical organization of the instrument into five second-order domains. Study 2, with 806 participants, successfully replicated the best model of study 1 against an alternative one. It is concluded that the YSQ-S3 is a valid and reliable instrument for the Colombian adult population. © 2024, Fundacion VECA. All rights reserved.