BACKGROUND: Team-based learning methods enhance course achievement, student success, and student satisfaction and are frequently used in nursing curricula. However, there is no valid and reliable tool for evaluating team-based learning in Türkiye. Adapting the Team-based Learning Student Assessment (TBL-SAI) into Turkish can provide a standardized and culturally appropriate evaluation tool, supporting nursing education practice and research. This study aimed to assess the validity and reliability of the Turkish version of the assessment (TBL-SAI-TR) among nursing students. METHODS: This descriptive and psychometrics study was conducted between October and November 2022. The sample consisted of 430 nursing students. The translation-back-translation method was used to determine the language accuracy of the scale. The content validity, construct validity, item analysis, and internal consistency analysis were used as psychometrics tests of the study. RESULTS: The Cronbach's α value of the TBL-SAI-TR was .90. The item-total correlations of the 23-item three-factor scale, validated by confirmatory factor analysis, were between .30 and .74, and the intraclass correlations were between .88 and .90. CONCLUSION: This study showed that the TBL-SAI-TR is a valid and reliable tool for assessing team-based learning among Turkish nursing students.