35 CT-guided percutaneous needle-aspirations with bacteriological sampling were performed in 21 patients suspected of pancreatic infection out of 122 patients with severe acute pancreatitis. Thirteen patients were found by smear and staining culture to have pancreatic infection, and diagnosis was confirmed by surgery. The pathogens found were E coli, pseudomonas and fungi. All pancreatic infections were in grade D or E according to the grading system of Balthazar. Seven of 8 patients with sterile aspirates were cured by nonsurgical therapy. We conclude that CT-guided aspiration is a safe, accurate method for identifying infection of the pancreas at the early stage of severe acute pancreatitis.