A 43-year-old woman with diabetic nephropathy underwent a Tc-99m MAG3 renal scintigraphy for the evaluation of renal function. Posterior images at 60 minutes demonstrated a migration of radiotracer activity beyond the lower pole of the left kidney, which might be incorrectly interpreted as urine leaks. However, the increased activities were moving along the bowel lumens over time. Another ring-like radioactivity was also seen in the suprasplenic region, and increased with time. These radioactivities were in the gastric fundus and gastrointestinal tract and caused by free Tc-99m pertechnetate.