Background Pancreatic endocrine tumors(PETs)are rare and their surgical treatment is often debated.The purposeof this retrospective study was to analyze the diagnosis and surgical strategy of functioning and non-functioning PETs.Methods From May 1980 to March 2006,36 patients with pancreatic endocrine tumors at the Second Affiliated Hospitalof Zhejiang University were retrospectively studied.Results Among the 36 patients,29(81%)had functioning tumors,and 7(19%)had nonfunctioning tumors.Ninety-twopercent of insulinomas were benign,whereas 4(57%)of nonfunctioning PETs were malignant.The size of functioningtumors was(2.3+0.3)cm,that of nonfunctioning tumors was less than(5.1±0.5)cm.The combination CT andtransabdominal ultrasonography resulted in a diagnostic sensitivity of 84%.Thirty-three primary lesions were preciselylocated in 32 patients(89%).Atypical tumor resection was performed for 73% of functioning tumors,while typicalpancreatectomy was performed for 6(85%)of nonfunctioning tumors.Moreover,5 liver resections and 1 lymph nodedissection were performed.During the follow-up,fifteen complications occurred in 12(36%)patients after operation.The5-year survival rate for patients with benign tumors was 92% compared to 50% for those with malignant tumors.Surgicalcure was achieved in 95% of patients with benign insulinomas.Conclusions Surgical strategy for PETs depends on the size and location of the tumor and the risk of malignancy.Theoptimal surgical procedure is key to prevent postoperative complication.Radical resection including initial and metastaticlesion may benefit patients with malignant PETs.Chin Med J 2007:120(17):1487-1490 Background Pancreatic endocrine tumors (PETs) are rare and their surgical treatment is often debated. The purpose of this retrospective study was to analyze the diagnosis and surgical strategy of functioning and non-functioning PETs. ​​Methods From May 1980 to March 2006,36 patients with pancreatic Endocrine tumors at the Second Affiliated Hospital of Zhejiang University were retrospectively studied. Results Among the 36 patients, 29 (81%) had functioning tumors, and 7 (19%) had nonfunctioning tumors. Ninety-twopercent of insulinomas were benign, but 4 %) of nonfunctioning PETs were malignant. The size of functioning tumors was (2.3 + 0.3) cm, that of nonfunctioning tumors was less than (5.1 ± 0.5) cm. The combination CT and transabdominal ultrasonography resulted in a diagnostic sensitivity of 84%. Thirty- Three primary lesions were precisely located in 32 patients (89%). Atypical tumor resection was performed for 73% of functioning tumors, while typicalpancreatectomy was performed for 6 (85%) of nonfunctioning tumo Fifty-seven patients occurred in 12 months (36%) patients after operation. The 5-year survival rate for patients with benign tumors was 92% compared to 50% for those with malignant tumors. Surgicalcure was achieved in 95% of patients with benign insulinomas. Confc Surgical strategy for PETs depends on the size and location of the tumor and the risk of malignancy. Theoptimal surgical procedure is key to prevent postoperative complication. Radical resection. including initial and metastatic lesions may benefit patients with malignant PETs. ​​Chin Med J 2007: 120 (17): 1487-1490