Background: Classroom social climate is a significant phenomenon within educational contexts; however, it has predominantly been studied among high school students, with limited evidence available at the university level and, consequently, in the psychometric properties of measurement instruments. This study aimed to analyze the psychometric properties of the University Classroom Social Climate Scale (ECSA-U) among Chilean students from the La Araucan & iacute;a region. Method: 422 students participated, responding to the adapted version of the ECSA-U and the Motivation subscale of the Motivation and Learning Strategies Questionnaire. Exploratory structural equation modeling (ESEM), reliability analyses, and correlation analyses were conducted to provide valid evidence for the Chilean University Classroom Social Climate Scale (ECSA-UCL). Results: The scale demonstrated a three-factor structure with good fit indicators, excellent reliability indices, and significant positive associations between the ECSA-UCL and the Motivation Subscale. Conclusions: The ECSA-UCL has proven valid and reliable for measuring the perception of Classroom Social Climate among Chilean university students, making it suitable for use as a measurement tool in studies or interventions that include this variable.