We describe an experimental model of acute pancreatitis in conscious rats, based on biliary reflux; sodium deoxycholate was injected while maintaining the common duct (biliary and pancreatic) temporally occluded. A progressive increase of serum amylase, cardiac rate and hematocrit value, as well as a decrease of plasma proteins are characteristic of this experimental model. Blood pressure was maintained until shortly before death, which occurred after 85 minutes. This is a simple model, reliable and reproducible, which requires minimal surgical manipulation.