Nonvisualization of gallbladder in cholescintigraphy has been established to be a major and reliable finding for acute cholecystitis. A rim of increased pericholecystic hepatic activity (PCHA or Rim sign) in conjunction with gallblader non-visualization was reported to be secondary sign of acute cholecystitis. To determine the frequency and significance of the pericholecystic hepatic activity we evaluated 217 cholescin-tigram in patients clinically suspeted of acute cholecystitis. After brief review of cholescintigraphic findings of acute cholecystitis the significance of the Rim sign is described. 1) The frequency of the Rim sign in surfically proved acute cholecystitis including gallbladder empyema and/or pericholecystic abscess (7/22) and in noncomplicated acute cholecystitis (3/45) was 31.8% , 6.6% respectively. The present study suggests that the Rim sign appear to indicate relatively high incidence of complicated acute cholecystitis and effort should be made observing the presence of the Rim sign in cholescintigraphy.