Objective: The Utrecht Work Engagement Scale-Student (UWES-S) has been extensively applied in different countries to assess engagement in students, but there are discrepancies about its factor structure outcomes. To analyse the factor structure of Utrecht Work Engagement Scale-Student as construct validity evidence and reliability in medical students. Methods: The non-experimental cross-sectional study was conducted at the public-sector University of Concepción in the Bio-Bio region in central Chile at the end of the first academic semester, between July and August 2017, and comprised students of health science undergraduate degree programmes in Medicine, Kinesiology, Pharmacy, and Speech and Language Therapy. Data was collected using a sociodemographic proforma and the Utrecht Work Engagement ScaleStudent. The subjects were randomly divided into groups A and B. With group A, exploratory factor analysis was performed using the method of extraction of the main axis analysis. With group B, confirmatory factor analysis was performed using the maximum likelihood method. Data was analysed using STATA 11 SE. Results: Of the 898 students, 538(59.91%) were females and 360(40.09%) were males. The overall mean age was 21.29±2.51 years (range: 17-34 years). Two factors,'involvement with studies'and'enthusiasm for the career', with eigenvalues 7.59 and 1.18 were identifi ed with the potential to explain majority of the total variance of items. Comparative fit index, Tucker-Lewis index and the root mean square error of approximation showed the solution having the best fit. Conclusion: Involvement with studies and enthusiasm for career were found to be critical factors, but did not show adequate adjustment even though confi rmatory factor analysis found this to be the solution with the best fit.