Studies on the pathophysiology of subdural hematomas (SDH) have been primarily focused on the acute phase and associated cortical injury, whereas the course of hematoma absorption remains poorly understood. Using a rat model of SDH, we have specifically investigated the correlation between neovascularization of membrane and the rate of hematoma absorption. Using improved surgical techniques, we have reduced surgery-related injury and increased the rate of generating successful SDH to 71.4%. With this model, we demonstrate that hematoma absorption was slow in the first 4 days and accelerated thereafter. The absorption rate and recovery of sensorimotor deficits were closely associated with neovascularization in the neomembrane characterized by the formation of arachnoid granulation-like structures at the interface between the hematoma and encapsulating neomembrane. Our data suggest that neovascularization in the neomembrane plays a key role in hematoma absorption and neuronal recovery. Furthermore, measures to enhance neovascularization could have therapeutic potentials.