Background: Erector Spinae Plane Block (ESPB) belongs to the family of fascial plane blocks in which local anesthetic is injected into a plane between two layers of fascia and subsequently spreads to nerves located within that plane or within adjacent tissue compartments. ESPB has been used in pain management, cervical, thoracic and cardiovascular surgeries. Objective: The goal of this narrative review article is to go through the pertinent anatomy, explain how the injectant spreads, show several ways to erector spinae plane block, and summarise case studies and clinical trials. Conclusion: Because the craniocaudal and vertical spread of local anesthetics and sensory block are not well understood or predicted, it appears that, unlike other blocks, the mechanism of erector spinae plane block and spread of local anesthetics will be decided by clinical data.