The aim of the present study was to investigate the relationship between Ag-NOR count levels and survival in 33 patients undergoing resection for ductal adenocarcinoma of the pancreas at Kanazawa University Hospital from 1985 to 1991. To determine the biologic behavior of invasive ductal adenocarcinoma of the pancreas, 33 tumors were classified into two groups according to the median value of Ag-NOR counts: Group 1, Ag-NOR count > or = 3.25 (higher Ag-NOR count group); Group 2, Ag-NOR count < 3.25 (lower Ag-NOR count group). As a result, we found that tumors with a higher Ag-NOR count were more likely to have liver or peritoneal metastasis than those with a lower Ag-NOR count, although the differences were not statistically significant. Tumors with lower Ag-NOR count levels were associated with favorable prognoses 2 and 3 yr after surgery, whereas those with higher Ag-NOR count levels were related to poor prognosis. Our results indicate that a Ag-NOR count level is a reliable prognostic parameter in resected pancreatic ductal adenocarcinoma.