Chronic venous access and repeated blood sampling for research purposes in large swine ideally should be possible without sedation, restraint or direct venipuncture of deep vessels. An operative technique of cranial vena cava catheterization and chronic catheter maintenance methods are described which were used successfully in the placement of 11 silicone rubber catheters in 10 animals. All were used for repeated blood sampling, as well as intraoperative infusion of medications and large fluid volumes. Long term patency was excellent with 10 catheters patent at the end of the study interval, up to 14 weeks after insertion. Serial blood sampling was accomplished easily without restraint. Catheter damage, infection or malfunction was rare. Proper maintenance and careful aseptic blood sampling render the cranial vena cava catheter a safe and reliable alternative to direct venipuncture in swine.