INTRODUCTION: An increasing number of patients with polyarticular course juvenile idiopathic arthritis are treated with biologics with great efficacy. Consequently, the importance regarding safety data in general as well as especially serious infections, incident autoimmune processes, or malignancies rises. In children, this is crucial concerning occurrences that manifest rarely and only after a prolonged latency period. AREAS COVERED: This study aims to analyze safety under therapy with the five most commonly used biologicals for the treatment of juvenile idiopathic arthritis in Germany: abatacept, adalimumab, etanercept, golimumab, and tocilizumab, and a control cohort, who received methotrexate. For this, data from the Biologics in Pediatric Rheumatology (BiKeR) Registry were analyzed with a focus on potential adverse drug reactions like serious infections, autoimmune processes or malignancies. EXPERT OPINION: Besides JIA category-specific differences, investigating side effects like severe infections and the development of additional autoimmune processes due to therapy is crucial. Future clinical randomized double-blinded studies are essential for direct drug comparisons, enabling optimal individualized therapy considering comorbidities and individual risks. Large patient data over a (life-)long period beyond childhood are particularly important, especially concerning the risk of malignancy after prolonged latency.