The objective of the present study was to assess the efficacy of bisoprolol in migraine prophylaxis. A double-blind placebo-controlled study was conducted in 226 patients with migraine with or without aura, a migraine history of at least 2 years and at least 3 documented attacks during the 28 days run-in period. The duration of treatment was 12 weeks following an initial 28 days‘ run-in period. Patients reported the number of attacks and their severity in a diary. Treatment with bisoprolol 5 mg resulted in a significant reduction in the frequency of migraine attacks (39% vs 22%) compared to placebo treatment (p<0.05). Treatment had no effect on the duration and severity of the attacks. Bisoprolol was well tolerated.