Introduction: Pulmonary hydatid disease is a parasitic infestation endemic in many sheep and cattle farming regions, particularly in Algeria. Complicated forms are a frequent occurrence and characterized by radio-clinical polymorphism and therapeutic difficulties. Material and Methods: This is a retrospective study (2017—2023) including 94 cases of complicated hydatid cyst of lung. Results: Complicated hydatid cyst of lung represented 22.76% of all hydatid cyst of lung treated surgically in our department. The average age was 27.8 years (4—56 years) with a slight male predominance 57.45%. The circumstances of discovery were dominated by cough in 54.26% and hemoptysis in 32.99%. The definitive diagnosis was made on the radio-clinical and biological findings. The treatment was surgical in all cases, conservative treatment was practiced in 87.03%, and parenchymal resection was performed in 16 patients. Postoperative hydatid recurrence was noted in only one patient. Conclusion: Hydatid cyst of the lung is a common zoonosis in Algeria. Its treatment is essentially surgical and must be initiated quickly once the diagnosis is established in order to avoid progression towards complications that are sources of diagnostic and therapeutic difficulties.