After a quadratus lumborum (QL) block, the course of QL plane catheter is unpredictable. This case series discusses the course and fate of trans-muscular QL catheters by following and discussing the contrast spread through the fascial planes. Intrao-peratively, the catheters were tracked by the surgeons and were checked for integrity of anterior thoracolumbar fascia (ATLF) by injecting sterile 0.9% saline. The ATLF was intact upon injection and there was cephalad and medial saline spread with slight bulging of ATLF. On day 3 after written informed consent from all patients, computed tomography (CT) contrast studies were performed. Post-operative contrast spread was variable and was visualised in transversus abdominis plane, QL plane, lower thoracic paravertebral space, inter-vertebral foramina and anterior epidural space. CT contrast images demonstrated a variable spread. In conclusion, injection in ATLF of QL can spread along the path of least resistance and is unpredictable.