The aim of this study is to present a novel use of Dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of a complicated iatrogenic chronic urethral injury. A 12-year-old boy with a neuropathic bladder presented a groove in the urethral mucosa due to chronic clean intermittent catheterizations (CICs) and suffered a posterior urethral injury during a failed catheterization for a routine examination. The defect on the urethral wall was repaired using Deflux, a technique that is not described in the literature. After the intervention the patient is continuing CICs without further complications.