The falx cerebelli is a midline vertical fold of dura mater positioned between the two hemispheres of the cerebellum. Together with the arachnoid mater, the dura mater envelops the entire brain, obscuring the grooves and folds on the surface of the cerebral hemisphere. However, in certain regions, the inner (meningeal) layer of the dura mater separates from the outer periosteal layer, extending into the brain and creating folds or partitions that support different brain regions.

One such dural partition is the falx cerebelli, located within the posterior cranial fossa. Its posterior edge attaches to the occipital bone, while its superior edge connects to the . The anterior edge of the falx cerebelli remains unattached.

The falx cerebelli houses significant venous sinuses along its margins, including the straight sinus at the junction with the tentorium cerebelli at the top, and the occipital sinus along the posterior edge.

In addition to the falx cerebelli, other vital dural partitions in the brain include the , the , and the .