Background and Study Goal. Stellate ganglion block (SGB) has been used in the treatment of cerebral derangements associated with headache, for the purpose of reliving spasm and presumably increasing the cerebral blood flow, normalizing endovascular resistance. Materials and Methods. 30 volunteers underwent unilateral SGB, 30–40 years (21 females, 9 males), with cluster headache. 5 ml 0,25 % ropivacaine were administered + 4 mg dexamethasone under C6 level paratracheal ultrasound guid. The confirmation was the presence of Horner´s syndrome. The resistive index (RI) was measured by ultrosound transcranial CV doppler of middle cerebral artery at the baseline and 1 min, and 10 min after SGB on both sides (the other side was taken for control). Normal values of RI corresponded to the age. Results and discussion. Our observations showed that after SGB in all patients there was a significant change in RI with normalization of cerebral blood flow, reduction or disappearance of headache. Conclusions. The difference between the block and the nonblock sides was significant before procedure (p < 0,0001) and after 10 min become the same with an insignificant difference (p = 0,001). A higher RI in patients with a cluster headache may be as an indicator for choosing the block side. Ultrasound technique will be helpfull for providing safe block and effect control.