The efficacy of intravenous acetaminophen (1000mg) in the treatment of acute migraine attacks as an alternative to parenteral application of lysine acetylsalicylate or triptans was investigated, using a multi-center, randomized, double-blind, placebo controlled study design. Migraine diagnosis was made according to the International Headache Society Classification. Sixty patients were included in three headache outpatient centers (Neurology Departments of the Universities of Regensburg, Münster and München). In the acute migraine attack patients were treated intravenously with either 1000mg paracetamol (acetaminophen) or placebo. The primary end point was pain-free after 2h. Secondary efficacy criteria were pain-free after 24h or pain relief after 2hours and after 24hours. With regard to the efficacy criteria, 37% of patients reported pain relief or painfree after two hours, 12 patients after treatment with acetaminophen and 10 patients after treatment with placebo. Out of these, 3 patients in the acetaminophen and 4 patients in the placebo group were painfree. After 24hours 86% of the patients reported pain relief: 24 treated with acetaminophen and 27 treated with placebo. The results indicate, that 1000mg intravenous acetaminophen is not superior to placebo in treating severe acute migraine attacks.