The efficacy of 99mTc cholescintigraphy in the diagnosis of gallbladder disease was studied in 116 patients. Sixty-one demonstrated gallbladder visualization (normal) and 55 had nonvisualization. In patients with acute abdominal pain, test sensitivity is 100%, specificity is 77%, and accuracy is 83% for the diagnosis of acute cholecystitis; no patient with gallbladder visualization had acute cholecystitis. Test sensitivity for any form of gallbladder disease is 66%, specificity is 82%, and accuracy is 71%; excluding patients with laboratory evidence of hepatobiliary disease, the predictability of acute or chronic cholecystitis increases to 100%. Cholescintigraphy demonstrated common bile duct patency in all eight post-cholecystectomy patients referred for evaluation of possible choledocholithiasis. Thus, gallbladder visualization with 99mTc-PIPIDA virtually excludes the diagnosis of acute cholecystitis, an abnormal test is a good predictor of gallbladder disease because of high specificity, and cholescintigraphy is extremely safe and simple to perform and may be used to demonstrate common bile duct patency.