A safe and reproducible method for placement of indwelling catheters into the portal venous system is a prerequisite for improved delivery of anticancer drugs to experimental liver metastases. Due to the lack of tumor models in large animals and the difficulty in establishing permanent access to the portal vein in rodents, this type of model has rarely been described in the laboratory setting. We propose a simple, minimally invasive method for repeated portal vein injections in rats. A vascular access device was used, which remained patent for periods of up to 3 months. Placement and support of the catheter tip in the portal vein was performed with a technique designed to avoid portal thrombosis and infections. Permanent portal vein access in a rodent model of liver metastases will be invaluable for the development of novel therapeutic strategies.