Background: Hydatid cyst disease is a major health problem in developing countries and it usually settles in the lungs in children. This study aimed to present pre-school children with lung hydatid cysts cases that underwent surgical treatment. Methods: The authors retrospectively investigated 42 consecutive pre-school patients who were diagnosed and surgical treated for hydatid cysts in their clinic between January 1998 and December 2011. Results: Seventeen (40.5%) patients were female and 25 (59.5%) patients were male. The average age of the patients was 5.2 +/- 1.3 (between 2-7 years). The most common symptoms were cough (74%), chest pain (26.2%), and fever (26.2%). Twenty-eight cases had cysts in only one lung; in five cases, the cysts were in a single lung and the liver, in six cases, in bilateral lungs and liver, and in three cases, in bilateral lungs. The average cyst diameter was 6.2 +/- 2.4 (2-12) cm. In five cases, there were combined interventions to the right lung and liver cysts with a transdiaphragmatic approach. Nine patients with bilateral hydatid cysts underwent operations. Muscle protector thoracotomies were performed in eight cases. Cystotomy and capitonnage were applied to all lung cysts. One patient underwent a bronchoscopy for postoperative atelectasis. In one case, postoperative fever was observed. There was no postoperative mortality. Postoperative average hospital stay was 7.2 +/- 2.1 (3-13) days. Conclusion: Surgery is the definitive treatment for lung hydatid cysts. The most important way to protect against the adverse effects of a thoracotomy is to eliminate the routes of transmission.