Key words:CIDR, CRL, BPD, FOD, Progesterone, PMSG, Ultrasound.The present study aims to evaluate the impact of controlled internal drug release (CIDR) in combination with prostaglandin F2α (PGF2α) and pregnant mare serum gonadotropin (PMSG) treatments on reproductive performance of dairy ewes and does besides, evaluation the accuracy of pregnancy diagnosis during the breeding season. Twenty female animals divided as Ossimi ewes (n=10) and Baladi does (n=10) were subjected to ovsynch regimen. Ultrasonographic examinations were conducted weekly using realtime B-mode ultrasound scanner by transrectal linear and transabdominal convex probes starting from day 14 post service. This study showed that estrus response was 100% in both ewes and does. The conception rates were 90% in ewes and 80 % in does. The incidence of twining was higher in ewes when compared to that in does with incidence rate 67% and 50 in ewes and does, respectively. The accuracy of ultrasound examination for determining fetal number was 100% for single and twin pregnancy. The birth rate was 100 % for both species; and this was confirmed at lambing / kidding. In conclusion, our results indicate that using biotechnologies such as ovsynch regimen and pregnancy diagnosis by ultrasonography are useful to improve the management of reproduction in ewes and does.