Lymphedema, a well known extraarticular manifestation of rheumatoid arthritis, has been rarely described in children with idiopathic chronic arthritis. We describe 12 cases of lymphedema and idiopathic arthritis of childhood seen at 4 different pediatric rheumatology centers. Eight patients were girls, 4 boys; the age at appearance of lymphedema ranged from 2.3 to 17 years. In all patients except one, lymphedema was localized to the lower limbs. The outcome of lymphedema was variable, but not always related to the arthritis course, and was mostly independent of any specific therapy. Lymphography was performed in only one patient, and revealed lack of lymphatic drainage in the affected leg. We conclude that the association of lymphedema and idiopathic arthritis of childhood is not rare; this association is unlikely to be coincidental, even though the pathogenetic mechanisms are currently not well understood.