Background: Placenta accreta occurs in the complete or partial absence of the decidua basalis. Women with previous cesarean delivery or placenta previa are known to be at greater risk of placenta accreta. Objectives: to evaluate ultrasound accuracy in diagnosing placenta accreta and its variants and to detect the potential value of uterine artery Doppler in diagnosing placenta accreta and to assess the impact of antenatal diagnosis in Egyptian population. Patients and Methods: This prospective study was conducted on (100) pregnant women diagnosed as placenta previa by ultrasonography and were candidates for either emergency or elective repeated CS or hysterectomy (if the diagnosis of placenta accreta is confirmed). All these patients were randomly selected from the Obstetrics Clinic at Beni-Suef General Hospital during their 3rd trimester. The study was approved by the medical ethics committee of Al-Azhar University academic and ethical committee and a written informed consent was obtained from all patients. Results: The results obtained from this study indicated no statistically significant differences regarding the mean values of uterine artery Doppler PI and RI between cases of placenta accreta and non accreta (p value =.078 & 0.58 respectively) in correlation with histopathological assessment. Our results showed no statistically significant correlation regarding mean values of uterine artery Doppler PI and RI between cases of placenta accreta and placenta non accreta (p values = 0.341, 0.953 respectively) in correlation with intra-operative assessment. Conclusion: Several ultrasound criteria can be used in diagnosis of placenta accreta, as this study showed their high accuracy. They include loss of retroplacental clear zone, presence of abnormal placental lacunae, myometrial thinning and utero-vesical hypervascularity. On the other hand, both loss of retroplacental clear zone, abnormal placental lacunae can predict which patient will mostly have CS hysterectomy.