Twenty-five inflatable and two semi-rigid rod type penile prostheses have been implanted in 27 patients with erectile failure following pelvic trauma. Reoperation was required in 13 patients in the inflatable prosthesis group but ultimate success and satisfaction were achieved in 92%. The etiology of erectile failure following various types of trauma is reviewed, as well as the approach to the evaluation of erectile failure in such a patient. Where etiology-specific corrective therapy is not possible, the penile prosthesis has proven to be an acceptable form of substitution therapy.