Purpose: Pancreatic intraepithelial neoplasia (PanIN) is one of the most commonly occurring precancerous lesion in pancreas which leads to development of pancreatic ductal adenocarcinoma (PDAC). We assessed the presence and grade of pancreatic intraepithelial neoplasia in the course of various diseases of the pancreas and its correlations with chosen clinicopathological parameters. null Results: A total of 276 foci of PanIN were identified in 94 patients. The most common lesions were PanIN 1a and PanIN 1b which together constituted 68.2 % of all lesions, whereas the PanIN 2 was present in 21.7% and PanIN 3 in 10.1% of patients. No statistical differences were observed in gender tendency for the development of PanINs. There was correlation between age of patients and degree of PanIN (p=0.034). There is no statistical difference in PanIN frequency among patients with pancreatic ductal adenocarcinomas, neuroendocrine tumors, chronic pancreatitis and pancreatic cysts (p=0.592). Conclusions: Our study showed that important factor in development of pancreatic intraepithelial neoplasia is age and the presence of PanIN in nonneoplastic diseases in older people should be included to the group with increased risk of cancer development.