The contributions to our present knowledge and understanding of diabetes insipidus are briefly surveyed. Though a disease presenting with polyuria and thirst had been recognized since Antiquity, it was not until the 17. Century the distinction was made between diabetes insipidus and diabetes mellitus. At the beginning of the 20. Century almost nothing was known about the function of the pituitary. It was generally believed that diabetes insipidus was a renal disease. Two clinical observations in 1912 suggested an association between the hypophysis and diabetes insipidus. This view was supported by the recognition in 1913 that extract of the posterior lobe of the pituitary was effective in diabetes insipidus. Despite much evidence to the contrary, it was assumed that the antidiuretic hormone was produced in the intermediate lobe of the pituitary. Around 1950 it was finally established that 'the posterior lobe hormones' are in fact secreted in the hypothalamus. At the same time the antidiuretic hormone was isolated and synthesized. More recently, progress within genetics has made it possible to characterize in details other rare types of diabetes insipidus.