Erectile dysfunction can happen after trauma, particularly with vertebral, pelvic, or perineal injuries. Penile Doppler ultrasonographic (US) findings in these patients are various, from normal to serious arterial impairment, according to the severity and type of injury. With neurogenic causes, Doppler US findings are usually normal, but decreased flow in cavernosal arteries may also be encountered due to combined vascular injury. With arteriogenic causes, relatively or absolutely decreased peak velocity in cavernosal arteries can be encountered. Alterations of penile arterial anatomy are frequently found in these patients and can be secondary changes due to proximal arterial insufficiency. After trauma in the penis or perineum, distortion or reconstruction of vascular anatomy in addition to traumatic sequelae in the erectile tissue can be directly visualized on Doppler US. Venogenic impotence can also be a result of trauma, and Doppler US findings are the same as nontraumatic venous leak. High-flow priapism is another category of post-traumatic erectile dysfunction, which can be diagnosed conclusively by Doppler US. It can be managed by angiographic embolization, and Doppler US is useful in evaluating recurrence and erectile dysfunction after embolization.