We present the first case of a patient born with congenital fusiform megalourethra who underwent the successful placement of an inflatable penile prosthesis (IPP) and mesh phalloplasty due to primary erectile dysfunction (ED). After an extensive psychosexual assessment and a preoperative MRI scan, an IPP was successfully implanted. The procedure was carried out through a penoscrotal approach, which offered excellent exposure to the crura and the proximal ends of the corpora cavernosa. Following the incision and the dilatation of both corpora cavernosa, the penile cylinders were inserted and a mesh phalloplasty was performed, to replace the erectile tissues lacking in the distal corpora cavernosa. After reservoir and pump placement, the device was tested, and no mechanical issues were recorded. The postoperative course was uneventful, and, at the 2-year follow-up, the patient reported highly satisfactory results, with valid functional erections.