Background: Treatment of alopecia areata (AA) is often empiric and not yet satisfactory. Recently, Janus kinase inhibitor showed promising results in Caucasians. Objectives: To investigate efficacy, tolerability, and hair growth trajey of oral tofacitinib monotherapy for Korean AA patients over extended period. Methods: This is a retrospective study of adult AA patients treated with tofacitinib monotherapy for least 4 months. Results: Thirty-six Korean patients with median initial SALT score of 98.9 were included; 91.7% had refractory AA. Twenty-nine (80.6%) patients demonstrated more than 5% SALT change. Twenty patients (55.6%) achieved 50% SALT change at median 7.5 months with 5 mg twice dosage. There were significant differences between SALT 50 achievers and non-achievers: duration of current episode (ρ = 0.009), duration of disease since first onset (ρ = 0.026) and age at onset of first episode (ρ = 0.011). Tofacitinib was well tolerated and there was no any serious adverse effect such as malignancy or tuberculosis reactivation. Conclusion: Oral tofacitinib monotherapy may be effective and tolerable in patients with AA. SALT 50 achievement was associated with followings: duration of current episode, duration of disease since first onset, and age at onset of first episode.