✓ Several methods of monitoring intracranial pressure (ICP) are in current use, each with its own advantages and disadvantages. The intraventricular line has been most useful because of the ability to withdraw cerebrospinal fluid to assist in control of elevated ICP. However, masses within the brain or generalized increased ICP may compress the lateral ventricle, making insertion of the catheter difficult or impossible. The intracerebral wick records hydrostatic changes too slowly to be used clinically. Swollen cerebral tissue may occlude the subarachnoid bolt thereby dampening the recorded pressure, and epidural monitors may give falsely high recordings because of irregularities of dura or bone. The authors have developed a flaccid-cuff catheter which has proven in animals to be an effective ICP monitor. There are several advantages, such as easy insertion into the centrum semiovale, rapid response to acute pressure changes, and continued sensitivity for periods of up to 3 weeks. The flaccid catheter cuff has no tension so that the pressure across the membrane is equal to zero, simplifying calibration. This type of cuff is necessary for maximum sensitivity to interstitial, brain-tissue, and gross ICP changes. The flaccid-cuff catheter may prove to be useful in a variety of situations such as after closed head trauma or intracranial surgery to assess elevated ICP caused by edema or evolving hematoma.