Background: Patent ductus arteriosus (PDA) is a part of the typical morbidity profile of the preterm infant, with a high incidence of 80–90% in extremely low birth weight infants born before 26 weeks of gestation. Whereas spontaneous closure of the ductus arteriosus (DA) is likely in term infants, it is less so in preterm ones. The aim of this study is to Evaluate Patent Ductus Arteriosus by using two dimensional echocardiography in infant and neonate. Method: The present study is a case-control study including 46 cases aged between neonate below 37 weeks of gestation to infant ˂6 months. This study was conducted in Neonatal ICU, Cardiology Unit and Pediatric Echocardiography Unit in Pediatric Department, Zagazig University. The period of the study was from January 2017 t0 December 2017. Results ECHO findings of both PDA cases and their controls were close to each other and there was no statistical significant difference between them except in size of left atrium which was significantly higher among PDA cases ranged from 0.91 cm to 1.7 cm with mean of 1.25±0.24, also ratio of LVED\ AO was higher among PDA cases than their controls and the difference was statistically highly significant. 9 cases (39%) of the studied PDA cases presented with high significant PDA, while 14 cases (61%) had low significant PDA.Concolusion: 1. Clinical assessment is somewhat helpful at detecting PDA early in the course of sick infants. Echocardiography is a safe method of detecting PDA and classifying it as HSPDA and LSPDA.