Two cases of delayed gallbladder visualization during Tc-99m RBC scintigraphy for gastrointestinal bleeding were reported. These patients had renal failure, hemodialysis, anemia, and multiple blood transfusions. The mechanism for delayed gallbladder visualization probably related to Tc-99m labeling of heme thus the radioactivity can be excreted in bile. When interpreting Tc-99m RBC scintigraphy in such patients, we should aware the possibility of delayed gallbladder visualization. And this may not represent hematobilia.