Spontaneous cerebrospinal fluid (CSF) pressure oscillations with a wavelength of 0.5-2/min (B-waves) are used as a criterion for shunt insertion in hydrocephalic patients. We describe CSF pressure oscillations in two nonhydrocephalic patients with normal baseline CSF pressure. Intracranial pressure was recorded via a ventricular drainage in a 54-year-old male who had a lumber CSF leak after surgery for lumbar spinal stenosis and disc herniation after the leak was closed. In the second patient, a 42-year-old male, CSF pressure was monitored via a lumbar drainage which was placed for treatment of a subcutaneous CSF effusion after resection of a recurrent temporal meningioma. CSF pressure oscillations of a wavelength of 0.5-2/min were observed with a relative frequency of 50% (patient 1) and 60% (patient 2) of the recorded time. Also longer waves were observed. Our data suggest that CSF pressure oscillations are not confined to hydrocephalic patients with raised intracranial pressure.