BackgroundCoronary artery disease (CAD) is a common cause of morbidity and mortality worldwide. Although catheter coronary angiography (CCA) is the gold standard in the diagnosis and management of CAD, coronary CT angiography (CCTA) has shown promising results for the same. MethodsCCTA was done using 40 slice multi-detector CT (Somatom Sensation, Siemens, Germany) machine in 220 patients of suspected CAD. Patients were classified as (a) normal (no calcific or soft plaque), (b) non-obstructive coronary disease (<50% stenosis), (c) obstructive coronary disease (>50% stenosis), or (d) a non-diagnostic study. Results96 (43.6%) cases were found to have normal coronary arteries on CCTA, 41 (18.6%) patients were classified as having non-obstructive disease, 67 (30.5%) patients were defined to have obstructive CAD, and 16 cases (7.3%) were inconclusive. Significantly obstructive triple vessel disease was noted in 4 (6%) cases. Double vessel disease was seen in 25 (37.3%) cases and single vessel disease was seen in 38 (56.7%). Single most common vessel with obstructive CAD was left anterior descending artery and was noted in 30 (44.7%) out of 67 such cases. The least affected vessel was left circumflex in 15 cases (22.3%). Median calcium score for non-obstructive CAD was 60 (range 30–95), and for obstructive CAD 300 (range 120–780). ConclusionKey benefits of CCTA lie in the avoidance of CCA since it has a high negative predictive value. CCTA has a definite role in post-stent and post-coronary artery bypass graft patients.