Current islet transplantation approaches have various defects. This study was to investigate the feasibility and safety of an indwelling catheter in the right gastric vein for intra-hepatic islet transplantation. Twenty patients had islet transplants through the indwelling catheter in the right gastric vein. The catheters were placed into the portal vein trunk using open surgery. While monitored with Doppler ultrasound, the islet suspensions were infused after the catheter location was confirmed in the trunk of the portal vein. The catheter was kept indwelling and secured to the skin for optional subsequent infusions and flushed with heparinized saline once per day to avoid peri-catheter thrombosis. After one month, the catheter was removed. Adverse effects and transplant efficacy parameters were observed. Insulin independence was finally achieved in 17 patients; 11 patients received a second infusion. The mean surgical duration was 55 ± 7 minutes and the hemorrhage volume was approximately 40 ± 11 mL. No significant change in portal pressure was observed (before infusion 2.9 ± 1.5 cm H₂O, after infusion 2.6 ± 1.7 cm H₂O, p>0.05). However, peak systolic velocity (PRV) of the hepatic artery after infusion was markedly higher than that before infusion (35.1 ± 10.7 cm/s vs. 68.5 ± 46.2 cm/s, p<0.01). Neither infection nor severe hemorrhage was found after surgery. It is feasible, convenient, and safe to use an indwelling catheter in the right gastric vein for islet transplantation.