Juvenile chronic arthritis (JCA) is a disease of unknown aetiology. As in the case of adult rheumatoid arthritis, infection, auto-immunity and heredity have been the principal aetiologic factors examined. The incidence is estimated at 0.01% of children at risk per year and the prevalence at 0.2–1 case per 100 000 children. Active controversy surrounds the correct terminology for the disease. Still’s disease applies to only one variant of the disorder and is, therefore, considered inappropriate as a collective term. Juvenile chronic polyarthritis is equally inappropriate since it neglects those patients with oligoarticular disease. The term juvenile rheumatoid arthritis has been used for several years, however the disease differs from its adult counterpart in such a variety of ways, that it is best avoided in favour of the term juvenile chronic arthritis (JCA). In particular nodule formation and seropositivity for IgM rheumatoid factor are unusual in JCA, and at initial presentation large joints tend to be involved more prominently than small joints (cf rheumatoid arthritis). Furthermore, iritis and pericarditis are relatively common in JCA, compared to rheumatoid arthritis.