With this experimental study we investigated the consequences of ligation of the common bile duct (CBD) on hepatic cells and on the renal ultrastructure by electron microscopy and also determine the effects after liberation of the ductus joint in order to clarify the mechanisms of renal failure commonly observed in cholestatic liver disease. The study was conducted on 53 Wistar albino rats divided into 4 subgroups. In the comparison group (sham) we proceeded to the simple laparotomy. After preparation of the common bile duct of all the rats of the four groups, and ligation of the duct at the level of the distal third, eight rats in each group were sacrificed on the 3rd, 7th, 10th and 14th day after surgery, taking blood samples to measure the serum levels of ALP and bilirubin, and liver and renal tissue samples for histological evaluation. In four rats of each group the common bile duct was unligated at the same deadlines to obtain free drainage of the bile for a week. At the end of this week, the rats were sacrificed by collecting blood and liver and kidney tissue samples. RESULTS: after CBD ligation in both groups, the ALP value, total and direct bilurubin levels were proportionally increased. After duct release, bilurubin levels decreased significantly. In group II, while large lipid granules were observed to indicate oxidative damage, mitochondrial swelling and crystals were observed after duct liberation. Areas of glycogen and normal mitochondria were observed in group IV. After duct release in this group, increases in Ito granules, lipid granules and normal mitochondria were observed, which may reflect the evolution of hepatic regeneration. When renal tissue was examined in group II, fusion processes in the feet, thickening of the basement membrane and mesengium were observed, and mitochondrial crystals were observed in renal tissue as well as in the liver after duct release. Damage in group III and group IV was increased parallel to prolongation of jaundice and after loosening persistent damage with mitochondrial crystals. CONCLUSION: Ultrastructural changes in rat liver tissue in conditions of obstructive jaundice may be reversible after restoration of drainage. On the other hand, ultrastructural changes in renal tissue in cases of prolonged jaundice are irreversible even if the internal drainage is restored.