The liver is a unique organ of human body because of its location and functions which enable normal homeostasis. The effects of different hepatotoxic substances cause micromorphological, ultrastructural and functional changes and liver disorders. Some researches of gentamicin toxic effect showed its hepatotoxic effect which caused a short-term functional liver disorder. Micromorphological and histochemical changes were examined in the liver of the rat treated with gentamicin. The research included 20 rats, the experimental (10 rats) and control group (10 rats). The experimental group was treated with gentamicin during the period of 8 days, while the control group was treated with physiological solution.In the experimental group of animals treated with gentamicin, slight degenerative... changes were found such as vacuolization of nucleus and granular changes, and vacuolar parenchymatousdegeneration (“unclearbubbling”) which are present in the periportal and intermediar zone of lobulus. There were no pathohistological changes in hepatocytes in the perivenular zone. Acute vein stasis such as dilatation of the central venula and capillaries were present. Boundary (regenerative) panel which consist of periportally localized hepatocytes is hyperactive and is manifested in large hyperchromic nuclei. The amount of glycogen is reduced in hepatocytes with vacuolar degeneration. In the perivenular zone, glycogen was present in the normal amount.In control group of animals treated with physiological solution, a clear lobular construction of liver was present.Hepatocytes are of polygonal shape and pink cytoplasm and centrally or paracentrally localized nucleus. The difference in construction of perivenular, intermediary and periportal zone was not noticed. Hepatocyteshad trabecular arrangement and sinusoidal capillaries in between. In the control group of animals, glycogen was stored in a larger quantity in the entire cytoplasm, in the form of purple- red granules.The distribution of glycogen in the zones was equal.The results of our experimental research showed a clear correlation between the application of gentamicin and the aforesaid changes.