The prediction of survival of patients with pancreatic cancer is usually based on tumor staging and grading and on the level of tumor markers. However, accurate tumor staging can be obtained only after resection, and still there is a great difference in survival rates among patients with the same clinicopathologic parameters. Recently the uptake of 18-fluorodeoxyglucose (FDG) by positron emission tomography (PET) has been found to be correlated with survival in patients with pancreatic cancer. This study evaluated the role of 18FDG PET as a prognostic factor for patients with pancreatic cancer. From June 1996 to July 2002, a total of 118 patients underwent PET for pancreatic cancer. The standardized uptake value (SUV) of 18FDG was calculated in 60 of them, and these patients were divided into high (>4) and low (< or =4) SUV groups. They were also evaluated according to the tumor node metastasis (TNM) classification system of the International Union Against Cancer, and by tumor grade, medical or surgical treatment, diabetes, age, sex, and CA 19-9 serum levels. Twenty-nine cancers showed high and 31 showed low SUVs. Survival was significantly influenced by tumor stage (P=0.0001), tumor grade (P=0.01), and SUV (P=0.005). Multivariate analysis showed that only stage (P=0.001) and SUV (P=0.0002) were independent predictors of survival. When patients who were analyzed for SUV were stratified according to the other variables, FDG uptake was related to survival also after stratification for the following: stage III to IVa (P=0.002), stage IVb (P=0.01), tumor resection (P=0.006), moderately differentiated tumors (P=0.01), age less than 65 years (P=0.006), CA 19-9 levels greater than 300 kU/L (P=0.002), and absence of diabetes (P=0.0001). The SUV calculated with 18FDG PET is an important prognostic factor for patients with pancreatic cancer and may be useful in selecting patients for therapeutic management.