Ten patients with juvenile rheumatoid arthritis (JRA) and growth failure were treated with recombinant human growth hormone (GH) for 1 to 3 years at a dosage of 0.57 IU/kg/wk. All the patients had been on prednisone at a mean dosage of 4.12 mg p.o. daily. GH was low in one patient, two patients had a borderline level and seven patients had adequate response to provocative tests or post-sleep measurement. Serum IGF-I was found to be low in five of six patients. Mean growth velocity increased from 2.45 cm/yr to 4.79 cm/yr after 1 year's treatment with GH (P<0.004). Six patients continued on GH treatment for a second year and continued to have a better growth velocity, with a mean of 5.43 cm/yr (P<0.014). Two patients entered puberty during the second year of GH treatment. This study demonstrates the potential beneficial effect of GH treatment in patients with JRA with growth failure of systemic onset or polyarticular onset who are on prednisone. Further study is needed to determine the long-term effect of GH treatment on ultimate height.