Serum and urine total alpha-amylase isoenzymes values were estimated in two groups of patients, who underwent either elective cholecystectomy and operative cholangiogram (group A-59 patients) or cholecystectomy without operative cholangiogram (group B - 68 patients). Serum and urine total alpha-amylase and pancreatic isoamylase (p-type) values were statistically significantly increased within the first 24 postoperative hours as compared to the preoperative levels only in group A (p less than 0.05). No clinical signs of pancreatitis were observed. Serum lipase alterations did not reach any statistically significant difference in either group. It is concluded that transient hyperamylasaemia after preoperative cholangiogram may be due to a reversible chemical pancreatitis caused by the infused opacifying agent into the common bile duct.