['Intra-articular corticosteroid injection (IACI), a common procedure in juvenile idiopathic arthritis, is usually associated with anxiety and pain. In a previous study, we concluded that nitrous oxide (NO2) provides effective and safe sedation for such procedures. Following the introduction of medical clowns in our hospital, we added them as an integral part of the team performing IACI.', 'To prospectively evaluate the effect of a medical clown on pain perception during intra-articular corticosteroid injection for juvenile idiopathic arthritis using NO2 conscious sedation.', 'Patients scheduled for IACI first met and interacted with the medical clown. During the procedure, the rheumatologist and the medical clown worked in parallel to create distraction. NO2 was administered. The patient, parent, physician, medical clown and nurse completed a visual analog scale (0-10) for pain. Change in heart rate ≥ 15% was recorded to evaluate physiologic response to pain and stress.', 'A total of 46 procedures were performed in 32 children: 23 girls, 9 boys, with a mean age of 10.9 ± 3.6 years. The median visual analog scale pain score for the patients, parents, physicians, medical clown and nurses was 2, 2, 1, 1 and 1, respectively. Five patients had increased heart rate and experienced increased pain.'] Do medical clowns facilitate nitrous oxide sedation during intra-articular corticosteroid injection for juvenile idiopathic arthritis?