BACKGROUND Ulcerative colitis (UC) is a chronic autoimmune inflammatory disease of the colon that infrequently affects children. The disease requires immunosuppressive therapy to achieve remission and keep the disease in remission. Currently, many therapies are approved for use in pediatric patients with UC, including steroid, 5-aminosalicylic acid (5-ASA), azathioprine, and biologic therapy with anti-tumor necrosis factor (TNF) inhibitors. Despite their efficacy, many patients have refractory severe disease that fails therapy and may require surgical interventions. Recently, the small molecule Janus Kinase (JAK) inhibitor tofacitinib has been approved for moderate to severe UC that fails biologic therapy in adults. However, the safety and efficacy of this drug has not been tested in pediatric UC patients. CASE REPORT We describe a case of a 13-year-old girl with 2-year history of severe UC who had secondary loss response to both infliximab and adalimumab over 2 years, despite adequate trough serum drug levels and the concomitant use of azathioprine. She was also dependent on steroid to control her disease. Infectious work-ups were always negative for infectious organisms. She was then successfully treated with tofacitinib 5 mg orally twice daily. She went into complete clinical, endoscopic, and steroid-free remission. CONCLUSIONS This case report highlights the safety and efficacy of tofacitinib in pediatric patients with severe refractory UC, potentially avoiding proctocolectomy in this young patient population. Future research should study the role of tofacitinib in patients with moderate to severe UC in children.