Lactoferrin, as measured in the pancreatic juice, has been thought to be of diagnostic value in chronic pancreatitis, but due to the hazards in cannulation of the pancreatic duct in the acute phase of pancreatitis the behavior of lactoferrin has remained obscure. In this study, lactoferrin levels were studied in pancreas tissue specimens obtained in ablative surgery for acute necrotizing pancreatitis (ANP) and in serum samples. A higher pancreatic lactoferrin content was found in ANP than in normal pancreas. Lactoferrin seemed not to leak from a necrotic pancreas in any considerable amounts into the circulation, as no differences were found in serum lactoferrin concentrations between ANP and controls. It remains an open question whether the lactoferrin increase is only an unspecific reaction in inflammation or is something specific for pancreatitis.