Aorto-ostial coronary lesions (AOLs) are important to detect due to the high risk of catastrophic consequences. Unfortunately, due to the complexities of these lesions, they may be missed on invasive coronary angiography. Computed tomography coronary angiogram (CTCA) is highly sensitive and specific in detecting AOLs, and has the additional advantage of demonstrating the surrounding anatomy. CTCA is particularly useful when assessing for AOL aetiologies in addition to atherosclerotic disease, e.g. Congenital anomalies, extrinsic Compression, Iatrogenic, Arteritis and Other, such as Thrombus, Embolism, Dissection and Spasm. This gives rise to "CIAO (TEDS)" as a proposed aide-mémoire and will form the structure of this pictorial review.