Acute pancreatitis is a serious surgical problem with a high incidence of mortality. Both ultrasound and X-ray CT have problems in identifying the extent and severity of the disease and the response to therapy. 67Ga-citrate has been used in 21 patients with clinically diagnosed acute pancreatitis: 9 patients had X-ray CT and 15 had US examination. Gallium scans were more sensitive than X-ray CT and US in detecting the extent and severity of acute pancreatitis. In addition, gallium was helpful to monitor the response to therapy when the scan was repeated at various intervals in three patients. A subtraction technique using 99mTc-tin colloid and 67Ga-citrate was helpful to mask the liver uptake of gallium and clearly identify the extent of acute pancreatitis.