Echinococcosis is a severe helminthic zoonosis largely caused by Echinococcus granulosus and frequently encountered in endemic areas.The liver and lung are the most frequently involved organs.Cyst rupture into the peritoneal cavity represents a rare but serious complication.Herein,we describe an acute occurrence of anaphylactic shock due to a spontaneous rupture of hydatid cyst in a 21-year-old Turkish patient unwittingly infected by Echinococcosis.Resection surgery of the perforated cyst in combination with cleaning of the abdominal cavity was performed.The patient rapidly improved and no relapse occurred during a follow-up of 8 months.Anaphylaxis is a serious complication of hydatid cyst rupture and needs to be promptly diagnosed.The main objective of our report is to underscore this life-threatening complication that should be considered when anaphylactic shock of unknown origin occurs,even in non-endemic regions.Moreover,we emphasize the need for a radical surgical approach to avoid widespread dissemination. Echinococcosis is a severe helminthic zoonosis substantially caused by Echinococcus granulosus and frequen encountered in endemic areas. The liver and lung are the most frequently involved organs. Cyst rupture into the peritoneal cavity represents a rare but serious complication. Herein, we describe an acute occurrence of anaphylactic shock due to a spontaneous rupture of hydatid cyst in a 21-year-old Turkish patient unwittingly infected by Echinococcosis. Review surgical of the perforated cyst in combination with cleaning of the abdominal cavity was performed. The patient rapidly improved and no relapse occurred during a follow-up of 8 months. Anaphylaxis is a serious complication of hydatid cyst rupture and needs to be promptly diagnosed. The main objective of our report is to underscore this life-threatening complication that should be considered when anaphylactic shock of unknown origin occurs, even in non-endemic regions. Moreover, we emphasize the need for a radical surgical approach to avoi d widespread dissemination.