Patients with chronic right upper quadrant pain who do not have gallstones on ultrasound or cholecystography are often referred for surgery for presumed acalculous chronic cholecystitis. We followed 26 patients who had cholecystokinin (CCK) cholescintigraphy for evaluation of chronic right upper quadrant pain without demonstrable gallstones on ultrasound who underwent cholecystectomy so that it could be determined whether there was any relation between a low ejection fraction (EF), morphological features of chronic cholecystitis, and clinical outcome. Eighteen patients (69%) were considered therapeutic successes, whereas eight (31%) were failures after an average 2-yr follow-up. Both patient groups had significantly reduced EF: the successful group at 0.39 and the failures at 0.25. Thus, a low EF did not predict clinical outcome, since the failure group had an even lower EF than the success group. Seven gallbladders demonstrated chronic acalculous cholecystitis; the average EF of this group was 0.35. The remaining 19 gallbladders were normal, yet also had an EF of 0.35. Thus, decreased EF does not predict the histologic features of chronic cholecystitis without gallstones. The diagnostic value of cholescintigraphy in patients with acalculous right upper quadrant pain is low, probably because this entity represents a variety of processes, including inflammation, gallbladder dysmotility, and the irritable bowel syndrome.