A 56 year-old women with a history of breast cancer underwent Tc-99m Hydroxymethylene Diphosphonate (HDP) bone scintigraphy at an annual follow-up, and abnormal focal uptake was observed in the right upper abdomen. However, subsequent single photon emission computed tomography/computed tomography (SPECT/CT) successfully delineated the uptake in a normal gallbladder. It was concluded that the abnormality had been caused by unusual Tc-99m HDP excretion and not by a metastatic lesion. Follow-up studies confirmed this diagnosis. This case demonstrates the usefulness of SPECT/CT in patients with unusual gallbladder uptake by bone scintigraphy.