Diseases of the parathyroid glands have always existed, affecting occasional individuals in every period and culture of the past. The significant changes in body build associated with their dysfunction must have attracted in the popular mind bewildering connotations that can be gleaned from their mythology. Although their associated clinical features were described in the medical literature, the presence of the parathyroid glands and their function went long unrecognized. In the relatively slow evolution of endocrinology, compared with that of other medical disciplines, the parathyroid glands and their diseases were one of the last to be defined. It was only in the latter part of the nineteenth century that the glands were identified in humans by Ivar Sandström (1852-1889). Their subsequent experimental extirpation by Eugene Gley (1857-1930), as well as others, led to the differentiation of the neuromuscular symptoms that theretofore had been attributed to removal of the thyroid glands. That these symptoms were the result of the hypocalcemia that ensues parathyroidectomy was suggested in 1908 by W. G. MacCallum (1874-1944) and Carl Voegtlin (1879-1960). The possibility that parathyroid pathology may be associated with skeletal abnormalities was made in 1914 by Jacob Erdheim (18874-1937), and in the following year documented by Z. Schlagenhaufer from the observation that in patients with osteitis fibrosa cystica, only one parathyroid gland is enlarged. This was to set the stage for parathyroidectomy beginning in 1925, for the alleviation of bone disease of hyperparathyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)