Background/Aims: Studies on long-term outcomes of adalimumab therapy in non-Caucasian patients with ulcerative colitis (UC) are lacking. Methods: We analyzed long-term outcomes of Korean UC patients treated with adalimumab at the Asan Medical Center, Seoul, Korea. Results: Between July 2013 and October 2018, adalimumab therapy was started in a total of 100 patients with UC (65 males [65.0%]; median age, 39.5 years [interquartile range, 23.3 to 49.8 years]; and median disease duration, 3.0 years [interquartile range, 1.0 to 7.0 years]). The median duration of adalimumab therapy was 13.5 months (interquartile range, 4.0 to 32.0 months). Eight of 100 patients (8.0%) received induction therapy only, four (4.0%) of whom ultimately underwent colectomy. Of 92 patients who received adalimumab maintenance therapy, 30 (30.0%) stopped adalimumab therapy due to loss of response, and one patient (1.0%) was lost to follow-up. Among the 92 patients who received adalimumab maintenance therapy, the cumulative proportions of patients remaining on adalimumab maintenance therapy were 70.0% at 1 year and 48.9% at 5 years. High partial Mayo score after 8 weeks of adalimumab therapy (hazard ratio [HR], 1.217; 95% confidence interval [CI], 1.040 to 1.425; p=0.014) and a history of exposure to two biologic agents before adalimumab therapy (HR, 4.722; CI, 1.033 to 21.586; p=0.045) were predictors of adalimumab discontinuation. Conclusions Long-term outcomes of adalimumab therapy in Korean UC patients appear to be comparable to those in previously published Western studies. Furthermore, previous exposure to multiple biologic agents before adalimumab therapy and disease activity after 8 weeks of adalimumab therapy were predictors of adalimumab discontinuation.