BACKGROUND/AIMS: The objectives of this real-world study were to determine 1-year persistence with vedolizumab in patients with ulcerative colitis and to evaluate factors contributing to loss of response. METHODS: In this multicenter, retrospective, observational chart review, patients with moderately to severely active ulcerative colitis who received >/= 1 dose of vedolizumab in clinical practice at 16 tertiary hospitals in Japan (from December 2018 through February 2020) were enrolled. RESULTS: Persistence with vedolizumab was 64.5% (n = 370); the median follow-up time was 53.2 weeks. Discontinuation due to loss of response among initial clinical remitters was reported in 12.5% (35/281) of patients. Multivariate analysis showed that concomitant use of tacrolimus (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.00-7.62; P= 0.050) and shorter disease duration (OR for median duration >/= 7.8 years vs. < 7.8 years, 0.33; 95% CI, 0.13-0.82; P= 0.017) were associated with discontinuation due to loss of response. Loss of response was not associated with prior use of anti-tumor necrosis factor alpha therapy, age at the time of treatment, disease severity, or concomitant corticosteroids or immunomodulators. Of the 25 patients with disease duration < 1 year, 32.0% discontinued due to loss of response. CONCLUSIONS: Persistence with vedolizumab was consistent with previous reports. Use of tacrolimus and shorter disease duration were the main predictors of decreased persistence.