Carotid body (lat. glomus caroticum) is a small structure of the size of maximally 7 mm of height and 4 mm of diameter and 2 mm of thickness located bilaterally and posteriorly to bifurcation of the carotid artery into internal and external carotid artery. It is a cluster of chemoreceptors detecting changes in the composition of arterial blood flowing through it. Recent research studies show that significance of its function may be greater than it has been previously established in the aspect of cardiology and oncology. Currently, in cardiology journals the high concern is devoted to the influence of chronically increased activity of carotid bodies on the progression of heart failure. In oncology it has been found that carotid body paraganglioma originating from carotid body known also as chemodectoma is the most common paraganglioma in the region of head and neck. In the authors' opinion it seems reasonable to gather the novel data on carotid bodies and to conduct research studies in order to make methods of determination of their morphology and function more perfect. In the present study a summary of the up-to-date knowledge on carotid bodies as well as on their pathophysiology and physiology has been made.