This study was designed to compare flunarizine, a cerebro-specific calcium channel antagonist, and propranolol in the prophylaxis of migraine with or without aura. Following a 1 month single-blind placebo baseline period, 94 patients were equitably randomised under double-blind conditions to take flunarizine 10 mg daily or propranolol 80 mg twice daily for 4 months. Both treatments led to a significant reduction in the frequency of migraines and use of rescue analgesics with a significantly greater decrease in number of attacks for flunarizine after 1 and 4 months. Neither treatment affected the severity nor duration of migraines. Overall, 67% of flunarizine patients and 51% of propranolol patients responded positively. Propranolol significantly reduced blood pressure and heart rate; flunarizine had no effect on cardiovascular function. Weight gain was noted with both treatments. Flunarizine is at least as effective as propranolol in the prophylactic treatment of migraine and may have a better safety profile.