Objective: To compare the efficiency of diagnosis of placenta accreta by grayscaleultrasound, and 3D power Doppler versus maternal level of serum alphafetoproteinin women with previous cesarean sections. 60 patients with previous cesarean sections after 36 weeks gestation sagedivided into 2 groups; cases group with placenta previa and control groupwith upper segment implanted placenta. Each group will be subjected toultrasound. Examination by greyscale ultrasound and 3D power Doppler,and maternal serum levels of alpha-fetoprotein are estimated. And thecondition of placenta is determined by the surgeon intra-operatively. Placenta accreta and its variants (including increta and percreta) wereconfirmed in 18 patients at the time of Cesarean delivery. We comparedgreyscale ultrasound to 3D power Doppler and MS-AFP, we found that MSAFPwas the most sensitive with 88.9 % sensitivity, followed by greyscaleultrasound with 77.8 % sensitivity followed by 3D power Doppler with 66.7 %sensitivity. However MS-AFP was the least specific with specificity of 33.3 %followed by greyscale ultrasound with 66.7 % specificity and the most specificwas 3D power Doppler with 83.3 % specificity. MS-AFP maybe useful as a complimentary technique with ultrasound(2D and 3D) for the antenatal diagnosis of placenta accreta. It could bealso used as a screening test for diagnosis of placenta accreta.