OBJECTIVE: To verify the interrater and intrarater reliability of Korean Wolf Motor Function Test (K-WMFT) for assessing upper extremity function after stroke. METHOD: Twenty patients with chronic hemiparesis after stroke participated in the study. The Wolf Motor Function Test consists of 15 functional tasks. Performances were timed and rated by functional ability scale. The K-WMFT were administered to the subjects by an occupational therapist. All test sessions were videotaped and scored by 2 physiatrists and another occupational therapist to examine interrater reliability. They were reevaluated at a later time by the same occupational therapist to examine intrarater reliability. RESULTS: Intraclass correlation coefficient of the performance time of K-WMFT was 0.94 and that of the functional ability scale of K-WMFT was 0.99. Intrarater correlation coefficient of the performance time of K-WMFT was 1.00 and that of the functional ability scale of K-WMFT was 0.97. CONCLUSION: The interrater and intrarater reliability of K- WMFT were verified. K-WMFT can be used as a reliable tool to measure upper extremity function of the stroke patients in Korea.