Background: One of the most consistently used justifications for the use of obstetric ultrasound is that, accurate diagnosis of fetal malformations before delivery can provide health care providers and parents a number of management options. Aim: evaluate the role of 4D ultrasound in assessment and detection of fetal congenital anomalies, in 1st & 2nd trimester of pregnancy. Subjects & Methods: Fifty women were examined by 2D followed by 4D US, and 52 detected anomalies. Results: Our results demonstrate an advantage of 4D US over 2DUS in 13 % of cases, equal findings in 30%, and less information in 17 % of anomalies detected. Four dimensional US is advantageous in some anomalies of the face and extremities only. Conclusion: 2D US remains the gold standard in assessment of fetal anomalies, and 4D US, therefore, is not a screening technique but an adjunct to 2D US for those fetuses in whom malformations are already determined or suspected on the basis of standard sonography.