To obtain a sample size sufficiently large to enable valid statistical analysis, patients with common or classical migraine treated in different centres with the calcium-entry blocker flunarizine, 10 mg daily, were pooled into 2 sets. In a first group of 202 patients, flunarizine was shown to reduce the frequency of attacks in 83%. Improvement was more marked when the duration of the disease was shorter and was more rapid when the pretreatment frequency of attacks was high. Somnolence and weight gain, sometimes labeled increased appetite, were the main adverse reactions but rarely caused withdrawal of the drug. Weight gain was significantly correlated with the global result and occurred more in patients with a low pre-treatment weight. In a second group of 125 patients, most of them being treated for a year, the effect of flunarizine was fully sustained at the 4-month level, i.e., at a median reduction in attacks by 51% to 60%.