Copyright: © 2023 Tanrıverdi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Medical professionalism is a basic competency in medical education. This study aimed to adapt the Professionalism Assessment Scale, which is used to evaluate the professionalism attitudes of medical students, into Turkish and to assess its validity and reliability. First, the scale's translation-back-translation was performed and piloted on 30 students. Then, the final scale was applied to medical students to ensure the scale's validity. The Penn State University College of Medicine Professionalism Questionnaire was used for external validation to assess criterion validity. Confirmatory factor analysis was performed for structure validity. Test-retest, item correlations, split-half analysis, and Cronbach's alpha coefficient were evaluated to determine the scale's reliability. SPSS 25.0 and AMOS 24.0 package programs were used for statistical analysis. The statistical significance level was accepted as P<0.05. The mean age of the participants was 21±2 years, and 50.5% (n = 166) were female. Three hundred thirty-five students were invited, and 329 participated in the study. The response rate was 98%. The mean total Professionalism Assessment Scale score was 96.36±12.04. The three-factor structure of the scale, “empathy and humanism,” “professional relationship and development,” and “responsibility,” was confirmed. The Cronbach's alpha coefficient of the scale was 0.94, and both the Spearman-Brown and Guttman split-half coefficients were 0.89. The three-factor structure of the scale, consisting of 22 items, explained 59.1% of the total variance. The intraclass correlation coefficient between test-retest measurements was 0.81. Confirmatory factor analysis showed a model suitable for the original version of the scale (χ2/sd = 2.814, RMSEA = 0.074). The Turkish version of the Professionalism Assessment Scale is a valid and reliable tool to determine the professionalism attitudes of medical students in Turkey.