Diagnosis of Chiari malformation (CM) is mainly based on morphological. The objective of this study was to quantify the evolution of CSF and blood flows dynamics before and after surgery treatment of CM. 21 patients who underwent surgery for CM, and presented good clinical outcome at 12 months were retrospectively included. We have shown that in CM, CSF flow is mainly reduced at the foramen magnum whereas it is normal at the cervical level. CM reduces jugular outflow. Complementary to the morphological investigation 2D PCMRI should be take in account to improve the evaluation of the severity of the Chiari Malformation.