Background/aim: This study aimed to translate and validate the Turkish version of the Hand20 questionnaire.Materials and methods: Patients who had upper extremity involvement and stable symptoms for the previous 4 weeks in their upper extremities were included in the study. Patients who were illiterate or used a splint during the day were excluded from the study. Participants completed the Turkish version of the Disabilities of the Arm, Shoulder, and Hand (DASH-T) questionnaire once and the final version of the Hand20 questionnaire twice in a 7-day interval. Internal consistency and reliability of the questionnaire was assessed. Moreover, correlations between Hand20 and DASH-T scores were analyzed using Spearman?s correlation coefficient.Results: A total of 104 patients participated in the study. The Turkish version of the Hand20 met the set criteria of reliability and validity. Internal consistency (Cronbach?s alpha = 0.93) and test-retest reliability were excellent (r = 0.82). Hand20 showed a positive and statistically significant correlation with DASH-T (r = 0.76, P