Cluster headache is perhaps the most painful of the primary headache disorders. Its treatment includes acute, transitional, and preventive therapy. Despite the availability of many treatments, cluster headache patients can still be difficult to treat. We treated 14 cluster headache patients with greater occipital nerve block as transitional therapy (treatment initiated at the same time as preventive therapy). The mean number of headache-free days was 13.1 + 23.6. Four patients (28.5%) had a good response, five (35.7%) a moderate, and five (35.7%) no response. The greater occipital nerve block was well tolerated with no adverse events. Headache intensity, frequency and duration were significantly decreased comparing the week before with the week after the nerve block (P<0.003, P=0.003, P<0.005, respectively). Greater occipital nerve blockade is a therapeutic option for the transitional treatment of cluster headache.