Purpose of Review: Ultrasound-guided quadratus lumborum block (QLB) is gaining popularity in regional anesthesia for various surgical procedures. The purpose of this review is to understand the relevant clinical anatomy, different mechanisms of actions, and techniques used for the block and clinical evidence so far. Recent Findings: The current data suggests a wide dermatomal distribution of the local anesthetic from T7-L2. The evidence regarding its utility is still evolving but has shown reduced opioid requirements for cesarean sections, lower abdominal surgery, and hip surgery. Prolonged analgesia has been reported as compared with more conventional transversus abdominis plane (TAP) block. This block has also been reported for above knee amputation, femoral-pop bypass, lumbar laminectomy and fusion, iliac crest bone graft, and iliac and acetabulum fracture. Summary: Quadratus lumborum can be performed through different approaches which requires sound knowledge of anatomy. Further research to determine which approach yields best results is warranted.