Aortic dissection was demonstrated incidentally by three phases bone scintigraphy in a patient with prostate cancer. Tc-99m RBC SPECT studies confirmed the finding. The studies evidenced the importance of (1) history taking before the procedures, (2) the value of the first two (arterial and tissue) phases of bone scan, and (3) RBC scan and SPECT studies in the investigation of dissection of aorta.