BACKGROUND: Liver transplantation in presence of diffuse portal vein thrombosis is possible by using caval blood as portal inflow, through cavo-portal transposition. However, clinical results are heterogeneous and experimental studies are needed, but similar hemodynamic conditions are difficult to obtain, especially in small animals. Herein we describe a new simple model of cavo-portal transposition in rat. METHODS: Spontaneous porto-systemic shunts are induced by subcutaneous transposition of the spleen. The presence of porto-caval shunts through the spleen permits the interruption of the main portal vein without splanchnic hemodynamic consequences. Cavo-portal transposition is achieved by anastomosing the inferior vena cava and the main portal vein after division of the pancreatic-duodenal vein. RESULTS: Selective angiography revealed total splanchnic blood diversion to the systemic venous circulation through the neoformed collaterals; macroscopical examination showed the absence of any signs of acute portal hypertension with normal liver and gut appearance. CONCLUSION: This model of cavoportal transposition is simple, effective and it simulates the clinical hemodynamic condition since the porto-systemic shunts induced by splenic subcutaneous transposition correspond to the physiological inframesocolic collaterals during chronic portal thrombosis in man.