The effective treatment of many diseases requires the use of multiple treatment strategies among which neuromodulation is playing an increasingly important role. Neuromodulation devices that act to normalize or modulate nerve activity through the targeted delivery of electrical stimuli will be the focus of this review. These devices encompass deep brain stimulators, vagus nerve stimulators, spinal cord simulators, sacral nerve stimulators and transcutaneous electrical nerve stimulators. Already, neuromodulation has proven successful in the treatment of a broad range of conditions from Parkinson's disease to chronic pain and urinary incontinence. Many of these approaches seek to exploit the activities of the autonomic nervous system, which influences organ function through the release of neurotransmitters and associated signalling cascades. This review will outline existing and emerging applications for each of these neuromodulation devices, proposed mechanisms of action and clinical studies evaluating both their safety and therapeutic efficacy.