A film showing the procedure for an occipital, or cisternal puncture, at the base of the skull. A demonstration is performed on a skeleton, showing where to insert the needle at the top of the spine, and base of the skull. The correct position is also shown by using an illustration of a cross-section of a brain. The operation is performed on a female patient. The skin on the neck is prepared with iodine and anaesthetic. The needle is then inserted and fluid is collected. The needle is withdrawn. The patient turns her head and smiles at the camera.