The aim of this study was to assess and validate the Korean version of the Boston Carpal Tunnel Questionnaire (K-BCTQ) in patients with carpal tunnel syndrome (CTS). After translation and cultural adaptation of the BCTQ to a Korean version, the K-BCTQ was administered to 54 patients with CTS; it was administered again after 2 weeks to assess reliability. Additionally, we administered K-DASH and EQ-5D to assess construct-validity. In a prospective study of responsiveness to clinical change, 29 of 54 patients were treated by ultrasonography-guided local corticosteroid injection therapy. The internal consistency of the K-BCTQ was high (Cronbach's alpha: 0.915) and the intra-class correlation coefficients were 0.931 for the symptom severity scale (P<0.001) and 0.844 for the functional severity scale (P<0.001). The construct-validity between the symptom severity scale and the K-DASH, and between the functional severity scale and the K-DASH were significantly correlated (both P<0.001). Clinical improvement was noted in 29 patients with injection therapy. The effect size of symptom severity was 0.67, and that of functional severity was 0.58. In conclusion, the K-BCTQ shows good reliability, construct-validity, and acceptable responsiveness after local corticosteroid injection therapy (Clinical trial number, KCT0000050).