Lumbar puncture is not a harmless procedure. Orthostatic headache is a common complication especially after diagnostic punctures. Increasing numbers of hemorrhages into the epidural or spinal space have been reported in recent times, most likely resulting from active thromboprophylaxis in connection with spinal and epidural anesthesia in surgical operations. All lumbar punctures are, however, associated with a risk for hemorrhage, particularly in those using anticoagulants such warfarin and low-molecular weight heparins as well as factor X and thrombin inhibitors. Neurologic complications caused directly during the puncture or from drug toxicity are mostly transient, persistent complications fortunately being rare.