Congenital heart diseases (CHD) are structural malformations of the heart or large vessels, which cause a functional impairment, present at birth, being discovered at that time or during the course of the life of the carrier. CHD are a group of complex diseases that cause a serious public health problem. the objective of the work was, to identify the most frequent congenital heart malformations in children under 1 year of age in the general hospital of the north IESS Los Ceibos of the city of Guayaquil (Ecuador) in the period July 2017- January 2018. The data of this investigation were taken from pediatric patients by reviewing medical records. In the study period, 35,105 pediatric care visits were made to children under 1 year of age. Around 1.025 (2.92%) cases of congenital malformations were detected, of which 108 corresponded to congenital heart malformations (CHD), that is, 10.53% of the malformations observed were of the CHD type. The most frequent cardiac congenital malformations in children under 1 year old are non-cyanotic congenital cardiac malformations (NC) with a total of 102 cases (94%) and 6 cases (6%). they correspond to congenital cardiac malformations (C), being these less frequent.