Reiter's Syndrome (RS) is not common in children and adolescents. From 1982 to 1987 we have seen 13 pediatric patients (8 male and 5 female) with clinical manifestations that characterized RS. Age of onset was 13 years. Clinical findings have been arthritis (100%) involving the knee and ankle joints, heel pain (84%), lumbosacral pain (38%). One to three weeks before joint involvement, six patients (46%) complained of urethritis, 5 (38%) had enteritis and two patients had both. 46% of the patients had HLA-B27 antigen. Radiologic findings were sacroileitis in five patients and calcaneal spurs. All patients were treated with non-steroidal antiinflammatory therapy and, in general, there was a clinical remission in 1-3 months. Nevertheless, after 4 years of follow up, 2 patients had acute relapsing arthritis and 4 had chronic arthropathy. Three patients have developed secondary ankylosing spondylitis. RS is not all that infrequent in pediatric patients with joint involvements if one looks for urethritis, enteritis, eye involvement and cutaneous manifestations. The clinical course is favorable, but there might be some chronic or relapsing cases. Some patients can developed secondary ankylosing spondylitis. For that reason a prolonged follow up of these patients is necessary.