Eight of 70 children with juvenile rheumatoid arthritis have developed iridocyclitis. This complication occurred more frequently in patients with monoarticular and pauciarticular disease (29%) than in patients with polyarticular disease (2%). Seven of eight patients with iridocyclitis have monoarticular or pauciarticular disease; none has had prominent systemic manifestations or evidence of ankylosing spondylitis. Iridocyclitis preceded joint manifestations in two of the patients and followed arthritis by 1 to 10 years in six of the patients. Activity of iridocyclitis and arthritis seemed unrelated; four patients developed iridocyclitis while arthritis was inactive. In seven children iridocyclitis began insidiously without acute symptoms. Eye involvement has remained unilateral in six patients. Six children have had significant decrease in visual acuity, and six continue to have active ocular inflammation despite therapy. Iridocyclitis is potentially a major cause of disability in juvenile rheumatoid arthritis. Early signs and symptoms may be minimal. Patients at risk are those with limited forms of joint disease. Early detection and therapy are crucial for prevention of permanent ocular damage. Careful eye examination should be a routine part of physical examination of children with rheumatoid arthritis, and periodic slit lamp examinations should be performed even when arthritis is in remission.