Despite a favorable clinical experience, there are little evidence existing about the effects of greater occipital nerve (GON) block in migraine treatment. In an open, preliminary trial we evaluated the use of GON block with 0,5 % bupivacaine, in prevention of migraine attacks. Ten women suffering from migraine diagnosed according to International Headache Society criteria were evaluated in a six-month study period. During the treatment and entire follow-up period, the patients avoided prophylactic therapy. Patients were given 3 times GON blocks with 0,5 % bupivacaine one week intervally. Afterwards blocks were repeated for a maximum 5 sessions depending on the clinical response. Clinical evaluation was assessed using a monthly Total Pain Index (TPI), and recording of the number of migraine attacks and analgesic consumption per month. At the end of the first month, TPI reduced from 308,3±55,2 to 114,1±4,7 (p=0,005). When compared to the values before treatment, it was seen that during the first month mean number of migraine attacks reduced from 12,6±4,8 to 4,9±1,8, mean analgesic consumption reduced from 11,0±3,4 to 4,9±1,1, and these reductions lasted up to six months. During the treatment no severe advers effect was seen in all cases. Although preliminary and obtained on a limited number of patients, our results show that the GON block with 1,5 ml of 0,5% bupivacaine does not have any severe advers effect and is effective in the prevention of migraine attacks.