The influence of jugular vein ligation on CSF resorption was examined experimentally by means of a manometric ventricular infusion test in dogs. Capacity of CSF absorption was decreased in a stepwise manner according to whether unilateral or bilateral ligation of jugular veins was performed. Interestingly, in addition to rises in ICP, dural sinus pressure was predominantly elevated after bilateral jugular ligation, often exceeding the ICP level. The CSF malresorption observed was considered to be closely related to the lowered pressure gradients between ICP and intracranial sinus pressure.