Twelve patients with biliary colic had no evidence of gallstones but underwent cholecystokinin-augmented hepatobiliary scintigraphy that revealed gallbladder ejection fractions of less than 35%. All 12 patients underwent cholecystectomy. Biliary colic was relieved in all patients at a mean postoperative follow-up of 2.5 years. The biliary colic in these patients was probably caused by abnormal gallbladder emptying, itself apparently produced by either cystic duct obstruction or abnormal motility. Biliary abnormality was seen at operation in most patients, and all patients had abnormalities of the gallbladder or cystic duct seen grossly or histologically. These abnormalities included cystic duct stenosis or adhesions, chronic inflammation, and cholesterolosis.