Pulmonary hydatidosis remains asymptomatic for a long time, and may be revealed following a complication such as intrapleural rupture. This entity, known as pyopneumothorax, poses a diagnostic problem even in countries with high hydatid endemicity. The aim of this study was to investigate the clinical, radiological and therapeutic aspects of pulmonary hydatid cysts revealed by spontaneous pyopneumothorax. This is a retrospective descriptive study of 5 patients with spontaneous pyopneumothorax revealing complicated pulmonary hydatidosis collected over 8 years at the Pneumology Department, CHU Mohamed VI, Marrakech, Morocco. Patients were younger and male. Clinical signs were dominated by cough and fever. Chest X-ray showed a hydroaeric image. Pleural puncture revealed a purulent fluid. Direct examination and culture of this fluid did not isolate any germs. All patients were drained and put on initial probabilistic antibiotic therapy. In view of the lack of clinical, biological and radiological improvement and the clinical presentation, we suspected complicated pulmonary hydatidosis. CT scan and thoracic ultrasound confirmed the diagnosis of ruptured KHP.