Background Hydrocephalus is an increase in cerebrospinal fluid volume leading to cerebral ventricular enlargement (ventriculomegaly). Phase-contrast magnetic resonance imaging is a sensitive technique to cerebrospinal fluid flow allowing noninvasive quantitative and qualitative evaluation of cerebrospinal fluid flow. Aim The purpose of our study was to assess the role of cerebrospinal fluid flowmetry using phase-contrast magnetic resonance imaging in evaluation of hydrocephalus in pediatric patients. Methods This prospective study included a group of 50 patients with ventriculomegaly diagnosed by a previous magnetic resonance imaging study. A control group of 20 subjects of matched age group were also included. All the participants were subjected to cerebrospinal fluid flow study. Results After quantitative assessment of cerebrospinal fluid flow at aqueduct level, the mean values of flow and velocity parameters were compared in both patients and control groups. The mean values in patients with aqueduct stenosis and Dandy–Walker malformation were significantly lower than those of the control group (no flow with hypodynamic circulation) with p < 0.001, < 0.017 for mean velocity, respectively, the mean values in patients with brain atrophy and Arnold–Chiari malformation, bilateral obstructive hydrocephalus at foramen of Monro were significantly lower than those of the control group (diminished flow with hypodynamic circulation) with p < 0.001, < 0.001, 0.046 for mean velocity, respectively, and 0.002, 0.001, 0.160 for stroke volume, respectively, the mean values in patients with communicating hydrocephalus and unilateral obstructive hydrocephalus at foramen of Monro were significantly higher than those of the control group (hyperdynamic flow) with p < 0.001 for mean velocity and stroke volume, and the mean values in patients with arachnoid cysts were within normal as compared to control group (normal dynamic flow). Conclusion Phase-contrast magnetic resonance imaging is a noninvasive technicality used for evaluation of cerebrospinal fluid flow both qualitatively and quantitatively for determining the type of hydrocephalus seen.