This study was undertaken in order to compare the reliability of two acute reflux pancreatitis models in rats, one performed by positioning a silicon tube in the duodenum and the other by creating a gastro-jejunal anastomosis. In two groups (A = 10 and B = 10 rats) a silicon tube was positioned in the duodenum; in the remaining two groups (C = 12 and D = 6 rats) a latero-lateral antecolic anisoperistaltic gastro-jejunal anastomosis was performed 30 days before surgery. A closed duodenal loop was created for 12 hours in groups A and C but not in B and D. Rats in both groups A and C developed acute pancreatic inflammation of a mild degree. Sham operated rats with silicon tube placement had higher histological damage scores than those with gastro-jejunal anastomosis. The difference found between the two groups of rats which underwent gastro-jejunal anastomosis was more marked than that between the two groups which had silicon tube placement. It was concluded that the creation of a gastro-jejunal anastomosis is probably the safer procedure to allow gastro-intestinal flow in acute reflux pancreatitis in rats.