ObjectivesTo examine the psychometric properties of the Maslach Burnout Inventory-Student Survey (MBI-SS) Thai version and to determine the frequency of burnout and correlation between burnout and associated factors.MethodsA cross-sectional study was conducted among undergraduate medical students using convenience sampling (n=545, 76.1% response rate, female 52.1%). Data were collected by a self-report survey. The MBI-SS was translated in Thai and tested for internal consistency using Cronbach’s coefficient alpha. A confirmatory factor analysis was performed using as fit indices of the chi-square and degree of freedom ratio (χ2/df), Comparative Fit Index (CFI), the Goodness of Fit Index (GFI), the Non-normed Fit Index (NNFI), Akaike information criterion (AIC) and the Root Mean Square Error of Approximation (RMSEA). Spearman and Kendall’s tau-b were used to identify correlations between burnout, depression and other factors.ResultsInterrater reliability was acceptable with Kappa of 0.83. Confirmatory factor analysis demonstrated good fit indices (χ2/df=197.62/83, CFI=0.97, GFI=0.95, NNFI=0.96, AIC=271.62 and RMSEA=0.06). Burnout had a weak, positive association with the PHQ-9 (r=0.294, df=2, p< 0.001). The screening depression score had a significant, modest positive association with emotional exhaustion (r=0.469, df=4, p<0.001) and cynicism (r=0.411, df=4, p< 0.001), and a weak inverse association with professional efficacy (r=−0.273, df=4, p< 0.001). ConclusionsThe Thai version of the MBI-SS had adequate psychometric properties among Thai medical students and can be used to assess burnout among undergraduate medical students in Thailand. Burnout was associated with risk for depression. Further studies on other associated factors contributing to depression are suggested.