Hydatid cysts, caused by Echinococcus species, are zoonotic diseases frequently observed in endemic regions worldwide, including Turkey. It is most commonly localized in the liver, followed by the lungs. Anaphylaxis and peritonitis, which develop after cyst rupture, are the most significant complications observed in these patients. Early diagnosis and prompt surgical intervention are extremely important. This study presented an extremely rare case of a hepatic hydatid cyst ruptured into the thorax, which may have high morbidity and mortality. A 24-year-old male patient presented to our emergency department with cough, dyspnea, fever, and allergy symptoms. He had a history of hepatic hydatid cyst surgery 5 years ago. Physical examination revealed urticarial lesions on the skin. The body temperature was 39 °C, and the pulse rate was 120 beats/min. Laboratory tests revealed leukocytosis and elevated C-reactive protein. Contrast-enhanced thoracic and abdominal computed tomography was performed. Diagnostic tests revealed that the patient had a ruptured hepatic hydatid cyst in the right thoracic cavity; hence, he was scheduled for emergency surgery. Laparotomy was performed via a right subcostal incision, and the ruptured cyst was located. It was understood that this cyst had fistulized into the diaphragm during a chronic process and subsequently ruptured acutely into the thorax. Partial cystectomy was performed for a ruptured liver cyst. The diaphragm was repaired, and catheters were placed in the thorax and abdomen for drainage. There were no other postoperative complications. Rupture of hydatid cyst disease is frequently observed in endemic regions. The rupture of a hepatic hydatid cyst into the thorax is an extremely rare event. In patients presenting with pulmonary symptoms who have a history of hepatic hydatid cyst surgery, the abdomen should always be thoroughly evaluated, and emergency surgery should be performed if required.