We used [99mTc]EHIDA hepatobiliary scintigraphy to determine whether both hepatic bile secretion and gallbladder contractility are suppressed in acromegalic patients receiving long-term treatment with the somatostatin analogue octreotide. We studied three groups of patients: group 1, untreated patients; group 2, average dose of octreotide 500 +/- 100 micrograms/day for 33 +/- 4 months; and group 3, 1000 +/- 200 micrograms/day for 33 +/- 4 months. Images were taken at specified time intervals during the 120-min period following injection of EHIDA. After a single injection of octreotide, group 1 patients demonstrated delayed visualization of the radioisotope in the liver, gallbladder, and duodenum. At the end of long-term treatment, group 2 patients showed a delay in appearance of maximal radioactivity in the gallbladder. Two weeks following discontinuation of octreotide, this parameter had decreased significantly (P < 0.001). In group 3, visualization of the liver, gallbladder, and duodenum were prolonged, with delayed visualization of the gallbladder persisting two weeks after withdrawal (P < 0.005). These results indicate that gallbladder contractility is decreased after a single injection of octreotide and that during chronic octreotide therapy the rate of bile secretion is reduced. Impaired gallbladder contractility normalizes more rapidly after discontinuation of octreotide in patients receiving low doses of the analog.