The analysis of scientific literature shows that the study of adrenal morphology in humans and animals is an urgent problem of biology and medicine from ancient times to the present day. In the historical aspect, we can distinguish three stages of studying the adrenal gland that differ in the directions of research. The first stage corresponds to the research of scientists of the XVI–XVIII centuries (Bartolomeo Eustachio, Andreas Vesalius, Gabriele Folloppio, Girolamo Fabrici, Andriaan Spieghel, Johann Vesling, Giulia Casseria, Caspar Bauhin, Johann Grafenberg, Caspar Bartholin, Thomas Bartholin, Giulio Casserio, Antonio Molinetti, Jean Riolan, Thomas Wharton, Giovanni Lancisi, Jakob Winslow, Antony Valsalva, Albrecht Haller, Johann Meckel, Jean Senac, Armand Cassan). Their works is devoted to the study of topography, macroscopic structure and function of the adrenal gland. Studies of morphological scientists of the second stage (late XVIII – mid XX century) correspond to the study of the structure of the adrenal gland at the microscopic level. Scientists like Albert Kelliker, Johann Ecker, Thomas Addison, Gabriel Colin, Alfred Kohn and Jay Arnold used histological and histochemical research methods. Edward Schafer, George Oliver, Vladislav Szymonowicz, John Abel, Jokiti Takmine, Welter Cannon, Edward Kendall to the study of the features of adrenal hormone secretion. Scientific works of the mid-twentieth and early twenty-first centuries can be combined in the third stage of research on the morphology of the adrenal gland. It is devoted to solving issues related to the formation of the adrenal gland in the process of filogenesis and ontogenesis, the features of the structure and function of the organ in normal and pathological conditions. A significant contribution to the study of the morphology of the adrenal gland of animals at the third stage was made by such scientists as Ziyade A. M., Dardykina O. N., Harina V. V., Atagimov M. Z., Torguj P. M., Antipin I. A., Shishkin A. P., Volkova M. V., Shevchenko L. F., Sidorova O. G., Vovchenko M. B., Salekh M. M., Ovcharenko N. D., Zaika S. V., Samatova I. M., Gorbacheva E. S., Pronin V. V., Kuznecov A. V., Pashinin N. S., Strel’nikova I. G., Barvenko A. D., Fedotov D. N., Izatulin A. V., Kvarackheliya A. G., Silkina A. V., Muhametov A. I. Among the studies of morphologists of the third period, the method of electron microscopy prevails.