Since the historic discovery of insulin in the early twenties by Frederick Banting and Charles Best, research has been concentrated on the elucidation of the mechanisms controlling secretion of hormones by the pancreas. These studies have yielded a wealth of information on the chemistry and regulation of both insulin and glucagon secretion. Several recent reviews have dealt with the myriad of chemical factors known to affect these hormones (82, 153, 185, 2 11, 243), but none has summarized the contributions of the nervous system. Since the original observation by Claude Bernard of ‘hyperglycemia after puncture of the floor of the fourth ventricle, many studies have implicated the nervous system in metabolic control and endocrine pancreatic function. Therefore we attempt here to review selectively the large amount of literature dealing with the neural control of the endocrine pancreas.