Triple rule out (TRO)-Multidetector computed tomography (MDCT) angiography denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination in patients with heart rate of upto 80 beats per minute. TRO MDCT Angiography is most appropriate for the patient who is judged to be at low to intermediate risk for acute coronary syndrome (ACS) and whose symptoms may also be attributed to acute aortic syndrome (AAS) or acute pulmonary embolism (PE). In this study we evaluated Noninvasive 256 slice MDCT Triple rule out angiography in fifty patients, in the diagnosis of different causes of acute chest pain.