We examined 59 consecutive patients presenting between 1993 and 2006 at our centre diagnosed with headache associated with spontaneous intracranial hypotension syndrome (SIH). Thirty-six (61%) patients were women; the mean age was 47 years (range 20-68). Cerebral MRI with contrast confirmed SIH in all patients. Headache characteristics were obtained by direct semistructured interview; in a minority of cases information was completed retrospectively through a phone call. All SIH patients suffered from headache. Early recognition of SIH may avoid dangerous worsening due to delayed diagnosis. Orthostatic headache, the main symptom, suggests the diagnosis.