In spite of the use of protoscolocidal agents during hydatid cyst surgery, a notable rate of disease recurrence in postoperation patients is still observed. The question remains whether living protoscolices lead to recurrence or the recurrence is due to the remainder of the germinative layer in the peritoneal cavity. The aim of this study was in vivo evaluation of different chemical (protoscolicidal) solutions on the germinative layer of the hydatid cyst. The germinative layer of sheep hydatid cyst was separated under sterile condition, divided into 0.25-cm(2) parts, and exposed to 0.5% cetrimide, 0.5% silver nitrate, 20% hypertonic saline, 15% dextrose and 25% dextrose, and normal saline as negative control for 2 min. The exposed germinative layers were implanted into the peritoneal cavity of 90 Balb/C mice (15 mice in each group). After nine months, the peritoneum was evaluated macroscopically as well as microscopically for the presence of any hydatid cyst. No hydatid cyst was observed in the peritoneal cavity of the exposed mice. The role of the germinative layer for inducing hydatid cysts in mice is questionable. However, the present study showed that the germinative layer had no role in the induction of hydatid cyst in these laboratory animals.