The height and height velocity standard deviation scores (HSDS and HVSDS) of 64 prepubertal children with mild to moderate chronic arthritis were calculated at the time of diagnosis and then annually during treatment and follow-up of 4 y. Preceding the diagnosis, children with chronic arthritis were as a group slightly taller than their healthy peers. During the year before the diagnosis they had grown faster than their peers. During the first year of treatment their growth velocity decreased (change in the mean HVSDS from +0.63 to -0.52), but during further follow-up it returned to the pretreatment level (the mean HVSDS being +0.53 four years after the diagnosis). The growth was influenced more by polyarticular than by pauciarticular disease. The cumulative total dose of glucocorticosteroids did not have statistically significant influence on growth. In conclusion, growth retardation in prepubertal children with chronic arthritis was seen following the diagnosis and initiation of treatment, more so in polyarticular disease. During further follow-up, growth velocity increased. This reflected the growth promoting effect of inflammatory process control.