['The aim of this study was to examine the relationship between birth weight, pulmonary artery (PA) size, and outcome in congenital diaphragmatic hernia (CDH) to establish if PA size has prognostic value.', 'The subjects for this study were 39 consecutive left-sided CDH patients treated at our institution according to the same protocol from 2002 to 2009. Other CDH patients with concurrent anomalies that eventually caused death or who became symptomatic more than 6 h after birth were excluded. Birth weight was used to create two groups; low birth weight (LBW; birth weight ≤ 2,500 g; n = 15) and normal birth weight (NBW; birth weight >2,500 g; n = 24). Right PA (RPA) and left PA (LPA) were measured by echocardiography (EC) during late pregnancy (fetal; gestational age (GA): 32-34 weeks), and on days 0, and 2 of life and compared.', 'Mean birth weights were significantly different between the two groups; however, gender, mean GA, and outcome were similar. In LBW survivors, RPA was significantly larger than in non-survivors. PA size was not related to outcome in NBW.'] Does pulmonary artery size have prognostic value in low birth weight infants with congenital diaphragmatic hernia?