---

Delayed intra cytoplasmic oocyte sperm injection (ÏÇSÏ) is referred to as using of delayed ÏÇSÏ method after failure of fertilization in ÏVF cycle. This method is proposed in old females due to poor quality of oocytes and as a result quality less chance of bertilization at ÏVF cycle. There are many reports on the success of the cycles after complete failure of fertilization. Ïn this method. Ïn this evaluation, three couples were under delayed ÏÇSÏ after fertilization failure in three cases, there was embryo developement and reached to the embryo transperring stage. Ïn two cases, were pregrant.