Biologics are recommended to treat paediatric ulcerative colitis (UC) that is chronically active or steroid-dependent despite aminosalicylic acids (5-ASA) and thiopurine treatments. Anti-tumour necrosis factor inhibitors (Anti-TNF inhibitors) are the agents of choice and vedolizumab could be considered as second-line biologic therapy.In the current case, we aim to describe a successful long-term treatment with vedolizumab in a 9-year-old boy with severe UC and primary non-response to infliximab. Concomitant azathioprine was used, and steroid refractoriness was also detected. Drug and anti-drug antibody levels were negative after infliximab induction so a switch to a 6-week-induction vedolizumab regimen followed by a maintenance regimen as a monotherapy was decided. The clinical response and tolerability to vedolizumab allowed long-term disease remission. Vedolizumab is currently non-authorised to treat paediatric patients and there is limited data on long-term treatments to date. This case contributes to the literature by adding evidence on the long-term efficacy and safety of vedolizumab in paediatric UC.