Objective: To investigate the clinical results of permanent implantation of radioactive 125 I seeds in treatment of advanced pancreatic adenocarcinoma.Methods:Eight patients with advanced pancreatic adenocarcinoma were treated with 125 I implantation from May 2002 to December 2002 and the data was retrospectively analyzed.Results: The mean number of 125 I seeds implanted was 22.8 with minimum of 19 to maximum of 38 each. The matched peripheral dose was 65 Gy.The postoperative courses were uneventful and no bone marrow suppression was recorded.The preoperative efractory abdominal and back pain in 2 patients were relieved completely (2/2).The postoperative CT scan which were done in four cases showed that tumor disappeared completely in 2 cases,were well locally controlled in 1 and slightly controlled in one.No acute pancreatitis and pancreatic leakage were encountered in all patients.Conclusion: The implantation of radioactive 125 I was effective in local control of the tumor and pain relief and is a safe alternative for the treatment of unresectable pancreatic adenocarcinoma.