The falciform ligament is a hepatic suspensory ligament that extends from the umbilicus to the diaphragm, containing the ligamentum teres and a vestigial remnant of the umbilical vein. Among the rarely-occurring pathologies of the falciform ligament, which include ligament cyst, tumor, abnormal vascularization, and congenital ligament defect, a falciform ligament abscess is even more sporadic. Accordingly, the definitive diagnosis of the falciform ligament abscess is rather challenging and may easily be misinterpreted as an infected choledochal cyst or a liver abscess. We present a 25-day-old infant with the falciform ligament abscess, which developed after the umbilical venous catheter insertion and was successfully treated with percutaneous drainage and antibiotic administration.