When working experimentally on dogs we have investigated the possibility of using an autogenous vein graft and polytetrafluoroethylene (Gore-Tex) prosthesis in the construction of the portacaval shunt. The portacaval shunt flow has been examined under similar hemodynamic conditions by experimenting on surviving dogs with the internal jugular vein and the above prosthesis. This study presents methods of research, hemodynamic measurements and the technique of portacaval shunt construction. After performance of the arteriovenous mesenteric-renal fistula we have succeeded in raising partially the portal vein pressure with the increase in the venous blood flow markedly higher. The portacaval shunt flow and the mesenteric-renal fistula have been verified by aortography and on autopsy. The jugular vein employed in the construction of the portacaval shunt remained unobstructed in 6 dogs (75 per cent) and the Gore-Tex prosthesis in 4 (50 per cent).