Objective To study the efficacy and safety of upadacitinib in children with refractory inflammatory bowel disease (IBD). Methods Clinical data of eight children with refractory IBD treated with upadacitinib at the Children's Hospital, Zhejiang University School of Medicine, from December 1, 2023 to May 20, 2025 were retrospectively collected to evaluate efficacy and safety. Results Eight children were included [Crohn's disease (CD), n=5; ulcerative colitis (UC), n=3]; seven were male and one was female. At baseline, six patients had mild disease activity (CD, n=4; UC, n=2) and two had severe activity (CD, n=1; UC, n=1). In UC, all three patients achieved clinical remission by week 2; the week-8 steroid-free clinical remission rate was 67% (2/3). In CD, after 4 weeks of upadacitinib, one patient achieved a clinical response and two switched to other drugs due to persistent activity; the week-12 clinical response rate was 20% (1/5). After 12 weeks, one additional patient switched therapy due to disease activity, and two received combination therapy with thalidomide and exclusive enteral nutrition, respectively. The median follow-up duration was 28 weeks. Overall, five patients achieved clinical remission; among CD, two achieved clinical remission at weeks 14 and 20, respectively. Among eight patients, one episode of norovirus infection occurred, complicated by hypovolemic shock. Conclusions Upadacitinib can induce a rapid response in children with refractory UC. In refractory CD, combining upadacitinib with agents of different mechanisms may increase the clinical remission rate. Multicenter studies with larger samples are required for confirmation, and vigilance for infection during treatment is warranted.