Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell–cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.