The spontaneous intracranial hypotension syndrome is a rare event but with increasing tendency. The clinical characteristics are comparable to those occurring after dural puncture and the most important clinical finding is the postural headache. The syndrome results from cerebrospinal fluid leakage but its etiology is still nearly unknown. The leaks are mainly located cervically or at the cervicothoracic junction. The syndrome may be associated with cranial subdural fluid build-up. Magnetic resonance imaging of the brain typically reveals diffuse pachymeningeal enhancement, frequently in association with displacement of the brain. Knowledge of this can be helpful to facilitate the diagnosis. Although conservative measures are often initially undertaken, placement of an epidural blood patch is the treatment of choice. Because of its similarity to postdural puncture headache, anaesthesiologists and pain therapists are increasingly involved in diagnosis and therapy. We report 2 patients with spontaneous intracranial hypotension. In addition to the cardinal feature of a postural headache, the patients suffered from subdural fluid build-up demonstrated by cranial magnetic resonance imaging.