Sympathetic blocks in the cervical and upper thoracic region are commonly used techniques for a variety of diagnostic, therapeutic and prognostic purposes. Stellate ganglion block is the common nomenclature utilized, however, stellate ganglion is present in only 80% of the population, thus, either lower cervical sympathetic block or upper thoracic sympathetic block is an appropriate term. The cervical sympathetic ganglia are identified as the superior, middle, intermediate and the inferior cervical sympathetic ganglion. The superior cervical ganglia are approximately 3 to 5 cm in length and situated on the longus capitus muscle anterior to the transverse process of the second, third, and rarely the fourth cervical vertebrae; the middle cervical ganglia are the smallest of the cervical ganglia situated on the longus colli muscle, anterior to the base of the transverse process of the sixth vertebrae; and the intermediate cervical ganglia which are more consistent in position and are located on the medial side of the vertebral artery. The inferior cervical ganglia, when present, are located on the transverse process of the C7 vertebrae, whereas the first thoracic ganglia are situated in front of the neck of the first rib. In 70% to 80% of the population they are fused together forming the stellate ganglion. Stellate ganglion block or lower cervical sympathetic block has been advocated for both diagnostic, therapeutic, and prognostic purposes for a variety of conditions. Even though multiple techniques are advocated in performing this block, fluoroscopically guided sympathetic blocks are more appropriate. Complications of stellate ganglion block include complications related to the technique, infection, and pharmacological complications related to the drugs utilized. Cervical sympathetic or stellate ganglion block is a very commonly performed procedure. If performed correctly, this can provide good therapeutic, prognostic, and diagnostic values.