The discovery of a hydatid cyst at autopsy poses the problem of its involvement in the mechanism of death. The aim of this study is to analyse the epidemiological and etiopathogenic characteristics of death attributed to hydatid disease, to discuss the mechanism of death and to propose preventive measures. This is a retrospective descriptive study of 26 cases of death with hydatid cyst autopsic discovered, collected at the forensic department of Fattouma Bourguiba University Hospital of Monastir (Tunisia) over a period of 27 years (from 1990 until 2017). In 26 cases, hydatid cyst was observed during autopsy of sudden death cases, which corresponds to 0.33% of the total of autopsies in this period. Of the 26 victims, 13 (50%) were men; the mean age was 43 years. Most victims were from rural zones (18 cases). In 20 cases, the complicated cyst was hepatic. It was cardiac in two cases. Of all cases, three cysts were cracked, and nine were broken. Of the 26 cases, only 15 were implicated in the death mechanism. Death was attributed to anaphylaxis in 12 cases, hydatid pulmonary embolism in 1 case, cardiac arythmia in one case and hemothorax in one case. Sudden death is the most dangerous complication of the hydatid cyst which can be discovered at autopsy. Several causes may explain its occurrence, the most common of which is anaphylactic shock.