The peripheral pharmacology of local mechanisms of penile erection is known today thanks to recent advance in the study of the regulation of erectile tissue smooth muscle tone. Smooth muscle fibers present in the corpus cavernosum and arteries destined to the penis relax in response to the release of non adrenergic non cholinergic neuromediators synthetized by postganglionic parasympathetic nerve fibers present in the cavernous nerves. Nitric oxide is the main proerectile neuromediator. Noradrenaline, released by sympathetic fibers, contracts penile smooth muscle fibers and is antierectile. Recent progress in the peripheral pharmacology of penile erection allows new perspectives in the treatment of erectile dysfunction. The spinal cord represents a major site for the neural regulation of penile erection. The latter occurs in response to stimuli from peripheral or supraspinal origin. Different neural structures in the brainstem (nucleus paragigantocellularis), pons and hypothalamus (nucleus paraventricularis) send projections to the thoracolumbar sympathetic and lumbosacral parasympathetic nuclei at the origin of proerectile peripheral pathways. Serotonin and oxytocin are candidates as neuromediators involved in the supraspinal control of penile erection. Studying the central command of penile erection allows an approach to the pathophysiology of psychogenic erectile dysfunction.