Critical thinking stands out as one of the most important cognitive abilities needed for effective adaptation to a knowledge-based society in the 21st century. Despite its significance, there remains a lack of consensus regarding the conceptual and methodological frameworks for measuring it. This study aimed to design and validate a comprehensive assessment scale for critical thinking. A specification table was constructed based on the critical thinking components agreed upon in the current literature, from which corresponding items were formulated and subsequently validated by expert judges. Following adjustments to the test, 258 Colombian participants completed it. Sample adequacy (KMO), Bartlett’s sphericity, and collinearity were confirmed, and the results underwent exploratory factor analysis. Reliability analysis was conducted using McDonald’s ω, Cronbach’s α, Guttman’s λ6, and Greatest Lower Bound (GLB) statistics. The final test comprised 17 items organized into 2 constituent factors, demonstrating robust content and internal structure validity, as well as high levels of precision and internal consistency (overall GLB of .93). The Critical Thinking Evaluation Scale (CTES) exhibits validity and reliability for use within the Colombian population. Its adaptation for other contexts and countries, both Spanish and English-speaking, is recommended. The Spanish version, along with the validated English version for potential adaptations, and scoring norms are provided in the attached documents.