Current surgical methods enable radical treatment of the most bulboventricular malformations (syn. conotruncal malformations, transposition complex). The defects, which were until now the field of embryologist and pathologist, require accurate and precise clinical diagnosis of the anomaly. The purpose of this analysis was to estimate the ability of angiocardiography for diagnosis of bulboventricular malformations considering the type of essential anomaly, its exact morphology and character of coexisting malformations. The report represents 49 cases with pathological diagnosis of bulboventricular malformations in children, in which during hospitalization angiocardiography has been performed. The cases were selected from 1918 angiocardiographies and also from 987 cases of pathological specimens with congenital heart diseases in the years 1970-1977. There were: 33 cases of TGA, in these 2 with corrected TGA, 3 cases of DORV, 1 case of DOLV , 12 cases of CV. All cases showed the broad spectrum of variants in position of the great arteries and kind of conus apart from type of basic anomaly. Septal defects, pulmonary orifice stenosis or atresia and anomalies of atrio-ventricular orifices particularly in common ventricle were mostly coexisting malformations. To recognize essential anomaly we estimated atrio-ventricular and ventriculo-arterial relation (connection), based on Kirklin classification. The conuses and position of the trunk of the great arteries were treated as pathomorphologic details, that had no influence on essential diagnosis of malformation. Arbitrary accepted definition and nomenclature was based on data from bibliography. Angiocardiography was made using full-size filmchanger AOT with maximal frequency 6 frames/sec. Contrast medium injected mainly into the ventricles. X-rays were performed usually immediately in two projections. Comparison of the angiocardiographic diagnosis with pathology of the hearts showed the correct diagnosis of the essential malformation, by means of angiocardiography, in more than 80% cases. But the diagnosis percentage in particular elements of malformation varied from 2/3 to 1/3 according to the type of malformation. The absence of the correct diagnosis of the essential anomaly, based on type of relations, was the lack of visualization of all heart cavities (in some cases), which was conditioned by the method. On the other hand the correct angiocardiographic diagnosis was sometimes impossible, because of very complicated anatomical situation in malformed hearts.(ABSTRACT TRUNCATED AT 400 WORDS)