During a 20-year period, 376 children with hydatid disease were treated at Hacettepe University Ihsan Doğramaci Children's Hospital. There were 223 males and 153 females with a mean age of 8.9+/-0.1 years. Hydatid cysts were localized in the lungs in 222 patients, in the liver in 56 patients, and in other organs in the remaining patients. Cough, fever, and abdominal pain were the most common symptoms. One hundred eight patients had medical, 182 patients had surgical, 73 patients had medical and surgical, and 4 patients had medical and percutaneous drainage treatment as the initial therapy. When evaluating the results of therapy, the relapse rate was higher in surgically treated patients than medically treated patients. We conclude that medical treatment of childhood hydatidosis is best, except in cases with complications such as infection, parenchymal compression or obstruction of airways, bile duct or viscera; all of these are indications for surgical therapy.