Forty-two patients with acalculous biliary tract disease were studied by means of cholecystokinin (CCK) cholecystography between 1959 and 1972. Comparing responses to CCK with normal responses in “control” subjects, several types of abnormal responses were recognized. Patients with cystic duct syndrome (CDS), previously identified, showed marked impairment of gallbladder emptying and minimal, if any, filling of bile ducts. Patients with partial obstruction at the sphincter of Oddi also showed impaired gallbladder emptying, but their common duct became prominent, dye refluxed into hepatic ducts, and no dye entered the duodenum. Sphincter spasm could be differentiated from sphincter stenosis by the response, or lack of it, to nitrates and/or anticholinergics. Marked hypercontraction of the gallbladder characterized patients with hyperplastic cholecystoses. All abnormal CCK responses were associated with reproduction of biliary tract pain. Treatment based on CCK cholecystography has been successful for a large majority of patients, with follow-up information ranging from 6 months to 11 years.