The possibility of using multiplanar reformations oriented on the axis of heart in diagnosing the common arterial trunk with X-ray computed tomography is substantiated. Examination data of 140 patients aged 1-19 days of life, 3030-3890 g body weight with conotruncal congenital heart diseases was analyzed, and common arterial trunk was detected in 7 patients (4 - boys, 3 - girls). In 5 (72%) patients, it developed mainly from the morphological right ventricle, 1 (14%) - completely from the morphologically right ventricle, and 1 more (14%) - evenly located above the ventricles. In four (57%) cases, the trunk valve had three leaflets, in two (28,5%) cases - two, in one (14,5%) case - four. All the patients had mitral-semilunar fibrous prolongation, intraventricular septal defects, doubled coronary arteries system, and the pulmonary arteries had their origin from ascendant part of common trunk. Pulmonary arteries had also their own common trunk in 4 (57%) cases, separate estuary in 3 (43%) cases. Aortic arc abnormalities included dextral aortic arc (2 cases), discontinuity of aortic arc (1 case), discontinuity of fourth aortic arc with persistence of fifth left aortic arc (2 cases). In general, computed tomographic angiocardiography heart-axis-oriented multiplanar reformations permit full and correct assessment of heart and main vessels, which is important for surgical treatment planning in congenital heart diseases.