Present diagnostic possibilities virtually do not make it possible to diagnose early stages of pancreatic cancer. Likewise, it is very difficult to differentiate between pancreatic cancer and chronic pancreatitis. The methods of visualization are insufficiently sensitive and the determination of certain genes could enrich our diagnostic opportunities. Considerable attention in this direction has been devoted to the determination and evaluation of the presence of oncogene K-ras. Our initial experience with the determination of K-ras in preparations from patients with pancreatic cancer or with chronic pancreatitis confirmed that K-ras in an oncomarker associated with adenocarcinoma of pancreas, whereas in patients with chronic pancreatitis it occurs in about 10% of the examined samples.