Abstract: The natural history of the echinococcosis can be studded with multiple complications; the most formidable is sudden death. We studied the epidemiological, pathological, and thanatological features of 34 sudden deaths due to hydatid cyst. The mean age was 33.2 years. A male predominance was observed with a sex ratio of 1.8. Most of our victims were from rural areas (79.4%). Sudden death was preceded by prodromal symptoms in 61.7% of cases. The most common was dyspnea (23.5%), followed by hemoptysis (11.8%). In 85.3% of cases, the cyst location was liver. It was cracked in 25 cases and broken in 6 cases. The rupture was spontaneous in 25 cases (73%). It was preceded by trauma in 7 cases. Death was related to an anaphylactic shock in 82.3% of cases, infection in 14.7%, and respiratory distress in 3% of cases. Sudden death is a serious and not exceptional complication of hydatid cyst. Several mechanisms may explain the sudden death.