The rat is useful in the continuing study of the pathogenesis of hepatic cirrhosis. Nutritional or toxic cirrhosis which closely mirrors human cirrhosis can be experimentally induced in this rodent. Hartroft and many other investigators have described in detail the pathologic alterations found in experimental liver disease in the rat.4-6With the development of new vascular techniques we embarked upon a project to perfect a suture method of portacaval anastomosis in this laboratory animal. Concurrently a similar technique has been developed by Lee and Fisher.8This paper summarizes our experience in developing these operations. In addition, we wish to present physiologic and pathologic data concerning the effect of portacaval shunts in the normal rat. Technique Sprague-Dawley rats of at least 300 gm. were used. With experience, shunts may also be performed in smaller animals without undue difficulty. Ether anesthesia proved to be the most satisfactory. Our initial efforts