Posture-dependent, post-lumbar puncture headache is most likely caused by continuous leakage of cerebrospinal fluid through the dura mater perforation with a consecutive downward sagging of the intracranial content and an irritation of pain-sensitive structures of meninges and blood vessels. A psychogenic co-factor may also play a role. It is generally acknowledged that the incidence and intensity of the headache correlate significantly with the diameter of the needles used. A second factor, the shape of the needle point plays a crucial role as is shown in our prospective, double-blind, clinical trial with 75 patients: employment of the "atraumatic" Sprotte needle with a rounded off point significantly reduced the incidence of postpuncture headache from 36% to 4%. Beside the discussion of pathogenic factors, remarks on a rational therapy are made.