Objective: is to assess intracranial CSF flow dynamics in pediatric patients with hydrocephalus suspected on morphological sequences using phase contrast MRI. Methods: A prospective observational study included eighty individuals from the pediatric population, 60 patients with ventriculomegaly and suspected hydrocephalus (diagnosed by a radiological report) who referred from Pediatric department and outpatients clinics of Al-Azhar University Assiut and 20 healthy control. Results: Patients were given diagnosis based on findings of conventional MR images, and were categorized into two major groups:-Group (I): Obstructive hydrocephalus (No.=31):-that subdivided into 3 sub-groups. Subgroup (Ia) Patients had aqueductal stenosis (No. =15).Subgroup (1) Patients had Arnold Chiari malformation. (No. =10).Subgroup (Ic) Patients had hydrocephalus with intracranial. SOL (No. =6).Group (II): Non Obstructive hydrocephalus (No. =29):-That subdivided into 3 sub-groups: Subgroup (2) patients had communicating hydrocephalus (no=16).Subgroup (IIb) 10 Patients had brain atrophy (No. =10).Subgroup (IIc) Patients had Dandy-Walker spectrum (No. =3). Conclusion: This technique enables measuring aqueductal flow parameters in a reliable and reproducible way and enable further future understanding of the pathophysiology of abnormal CSF dynamics in cases of hydrocephalus that still appears vague. The optimal cut of value of hypodynamic CSF flow through cerebral aqueduct in comparison of all obstructive subgroups with control group is the 7.5 μl, with sensitivity 100%, specificity 64% and P value > 0.05. The optimal cut of value of hyperdynamic CSF flow through cerebral aqueduct in comparison of non-obstructive subgroups with control group is the 37.5 micro-liter with sensitivity 100%, specificity 40% and P Value > 0.05. Cine Phase images can detect spontaneous third ventriculostomy that may occur in some cases of long standing hydrocephalus.