The kidneys of patients with autosomal dominant polycystic kidney disease (ADPKD) usually continue to increase in size even after patients begin dialysis, and mass effects can lead to severe complications. Thus far, renal manifestations of this disorder have been discussed only from the viewpoint of cyst formation or cytogenesis, not from that of vascular abnormality. Because kidneys in ADPKD patients are usually supplied by well-developed arteries, we attempted renal contraction therapy in ADPKD patients with renal transcatheter arterial embolization (TAE) using intravascular coils. Mainly peripheral branches of renal arteries encircling the cysts were embolized. Our treatment has been confirmed to be effective in 266 patients until 2005. Renal size continued to decrease to 53% of the pre-TAE after 1 year. Almost all patients have had improved quality of life and nutritional status. We next tried TAE in 76 intractable patients with symptomatic polycystic liver. We tried to embolize only the hepatic segments replaced by cystic lesions in which the hepatic arteries were well-developed but the intrahepatic portal vein was obstructed. Sixty-four patients have had a good clinical course with this method. Based on our observation of ADPKD through treatment with TAE, we speculate that cyst growth in both the kidney and the liver progresses via the mechanism of ‘arteriogenesis’ of large vessels as well as ‘angiogenesis’ of small vessels.