Hydatid disease is a zoonosis caused by a larva of the tapeworm Echinococcus. All organs can be involved, but it is frequently located in liver for adults and lung for children. The clinical features are nonspecific. Imaging findings has an important place in the diagnosis and the follow-up. Rupture is the most common complication of a hydatic cyst and has a variety of imaging findings depending on the ruptured layer, the amount of air within the cyst and the type rupture. We report the case of a 10-year-old boy presenting shortness of breath and fever among other symptoms revealing by chest X-ray and thoracic CT scan, a lung ruptured hydatic cyst to the pleural cavity causing a tension hydro-pneumothorax and a superadded infection.