The intrathoracic rupture of a splenic hydatid cyst is very unusual. We report herein the case of a 29-year-old man who presented with a left-sided pleural effusion associated with fever and chest pain. The patient underwent laparotomy and splenectomy en bloc with a portion of gastric wall and diaphragm, followed by irrigation of the pleural cavity with a hypertonic solution through a phrenotomy. His outcome was favorable and there was no recurrence at 2-year follow-up.