Pain is the major symptom of children with juvenile idiopathic arthritis (JIA) and its reduction is a key goal of treatment. It is widely agreed that assessment of pain is a fundamental component of the rheumatology evaluation and should be carried out at each clinic visit. However, so far there has been insufficient attention to the impact and causes of pain in children with chronic arthritis in both clinical practice and research. Quantitative measures of pain are seldom used regularly in daily care and pain assessment has not been incorporated in the most popular composite outcome measures for JIA, including the criteria employed to measure improvement in therapeutic trials. A recent advance in the development of pain tools involves mobile devices, particularly smartphones, and the internet to collect real-time self-reported data via electronic diaries. Concern has been raised by the recent observations of persistence of pain in some children with JIA despite adequate treatment with the modern biologic medications and good disease controls. These findings underscore the need of large-scale studies of the prevalence and determinants of pain in patients treated with contemporary care. In addition, the reasons that explain the persistence of pain after the resolution of the inflammatory process should be investigated through research on neurobiological mechanisms of pain and by addressing the role of factors external to the disease, such as mood, anxiety, and pain sensitisation and coping