Background: Placenta accreta occurs when there is an abnormal adherence of a part or entire of the placenta to the uterine wall with either partial or complete absence of the decidua basalis. Objective: This study aimed to investigate the role of uterine artery Doppler in the diagnosis of placenta accreta in patients with placenta previa. Patients and method: This study prospective cohort study was done at Maternity Hospital, Zagazig University. The study included 36 pregnant women with placenta previa attending for antenatal care or emergency department. All patients were subjected to full history taking, ultrasound examination and colour Doppler was performed using: VOLUSION 730 prov (2D Doppler) of 5 MHZ. Result: The main gray scale ultrasound features were presence of vascular lacunae with a sensitivity of 96% and specificity of 89.1%, absence of RPS with a sensitivity of 76% and specificity of 32.7%, myometrial thinning with a sensitivity of 76% and specificity of 34.51%, absence of RPS and vascular lacunae with a sensitivity of 80% and specificity of 56.4%, absence of RPS and myometrial thinning with a sensitivity of 82.2% and specificity of 56.5% and myometrial thinning and vascular lacunae with a sensitivity of 76.4% and specificity of 34.5%. All signs with a sensitivity of 68% and specificity of 96.4%. Conclusion: The use of gray scale ultrasound and colour flow Doppler is a good tool in diagnosis of placenta previa accreta. Addition of uterine artery Doppler indices could predict placenta accreta in cases of placenta previa.