A group of 76 children with early onset pauciarticular juvenile chronic arthritis (JCA) was studied in order to establish different disease patterns and to try and identify parameters associated with an unfavourable outcome. An intermittent pattern of disease was found in 60 children (79%). Of the remaining 16 patients continuous persistent pauciarticular disease activity was present in 7 (9.2%) and extended pauciarticular in 9 children (11.8%). An extended pauciarticular pattern was seen predominantly in children with continuous disease activity. It appeared to be impossible to predict the course of the disease on the basis of clinical parameters. The frequency of complications, such as local growth disturbances or psychosocial problems and of chronic anterior uveitis resulting in visual handicap correlated with continuous disease activity. The extended pauciarticular pattern, resulting in polyarthritis resembled seronegative polyarticular JCA, underlining previous reports that the joint pattern during the course of disease may be more important than joint pattern at onset of disease.