Hydatid disease is a wide spread disease. It is endemic in Tunisia. Man is contaminated by digestif way and by living with dogs. The disease affects usually liver and lung. Other localisations are rare. Hydatid cyst of the ovary is uncommon and clinically they present like malignant tumour of ovary. We present 7 cases of hydatid cyst of the ovary and we discuss the characteristics of this site of the hydatic disease.