The autonomic nervous system has a cranio sacral parasympathetic and a thoraco-columbar sympathetic outflow, each of which supply every organ in the body. Autonomic dysfunction is common after spinal injuries, especially in high lesions where there is substantial disruption to descending spinal sympathetic and sacral parasympathetic pathways, which are separated from cerebral control. This can result in cardiovascular, sudomotor and pelvic dysfunction (the latter involving bladder, bowel and sexual organs), and impair key integrative control mechanisms that maintain blood pressure, heart rate and body temperature. This overview will focus on cardiovascular and sudomotor autonomic dysfunction that results from spinal cord injury; dysfunction which can result in considerable morbidity, and sometimes in death. Autonomic abnormalities will also be considered on a temporal basis, in the stage of spinal shock and later in the chronic stage. The pathophysiological mechanisms that form the basis of therapeutic strategies to overcome the key features of autonomic dysfunction will be described. Newer approaches which quantify autonomic dysfunction, especially in relation to a more complete classification of spinal cord injuries will be discussed, as this has major implications in relation to newer repair interventions that reverse spinal injury.