A retrospective analysis of clinical and operative data was made covering 56 cases with combined coarctation of the aorta and patent ductus arteriosus. Prior to surgery both anomalies were recognized in 27 patients. Clinical data failed to furnish an reliable criteria as to the difference in anatomic variants of combined aortic coarctation and patent ductus arteriosus. The clinical picture and diagnosis of this congenital pathology are largely contingent upon the conspicuousness of each abnormality and consequently, on a definite orientation of the clinical diagnosis. There is a direct relation between the frequency of detection of the patent ductus arteriosus and its size.