BACKGROUND Juvenile chronic arthritis (JIA) is a major paediatric rheumatic disease. OBJECTIVE The aim of this study was to determine how physical development in children with JIA was affected by the subtype of the disease and by the type of therapy used. METHODS Data were collected at the Sunbeam Center for the Diagnosis and Treatment of Childhood Illnesses in Wrocław, Poland. The study group included 82 children from 4 to 18 years old that were diagnosed with juvenile idiopathic arthritis. The duration of the disease ranged from 3 months to 15 years, with a mean of 2.9+/-2,8 years. At the time the subjects were examined, the disease was either very mild, inactive or in remission. Because the subjects varied in terms of age, all data were standardized and recorded in terms of numbers of standard deviations away from the age-specific and sex-specific means for the reference group, which consisted of healthy children and adolescents from Warsaw, Poland. RESULTS In the subjects in this study, height and weight were insignificantly lower than in their healthy peers. Body height and body weight were negatively affected only in children treated with corticosteroids for more than one year. Serious growth disorders were observed in 5 subjects (6%). Chest depth and chest width were significantly lower. CONCLUSIONS Strong relationship between the growth retardation and long-term steroid therapy has been pointed out.