The authors have developed a new model of flewible metal prosthesis to maintain the urethral calibre throughout the period of healing and epithelial restoration following internal urethrotomy. It consists of a large intravesical spiral, a shaft within the prostatic and sphincteric urethra and a spiral in the bulbar and anterior urethra. This prosthesis, implanted in 7 patients for periods ranging from 2 to 5 months, provides additional calibration following internal urethrotomy, but a longer follow-up is necessary to assess its real efficacy.