Naproxen was compared with placebo in a double-blind, crossover trial in classic and common migraine. The trial was terminated at a fixed date; 37 patients had entered, 5 of whom were excluded. Naproxen was given as 750 mg at the first symptom of the attack, a total of 1250 mg per 24 h was allowed. Patients were followed for six attacks or three months in each phase, whichever came first. The severity of the headache was significantly less with naproxen in the first 2 h of the attack (p = 0.047), whereas there was no difference when the whole attack was considered. Significantly more patients preferred naproxen (p = 0.042). Side effects occurred in five patients, causing withdrawal of one patient while on naproxen.