BACKGROUND: Infants with congenital heart defects (CHDs) have increased risk of childhood morbidity and mortality. However, little is known about racial/ethnic differences in early childhood mortality. PATIENTS AND METHODS: We conducted a retrospective cohort study with data from the Texas Birth Defect Registry on 19 530 singleton, live-born infants with a CHD and born January 1, 1996, to December 31, 2003, to non-Hispanic (NH) white, NH black, and Hispanic women. Texas Birth Defect Registry data were linked to Texas death records and the National Death Index to ascertain deaths between January 1, 1996, and December 31, 2005. Kaplan-Meier survival estimates were computed, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from multivariable Cox-proportional hazard regression models to determine the effect of maternal race/ethnicity on mortality for selected CHD phenotypes. RESULTS: After adjusting for covariates, compared with NH white children, NH black children had increased early childhood mortality risk for transposition of the great arteries (HR: 2.04 [95% CI: 1.40–2.97]), tetralogy of Fallot (HR: 1.85 [95% CI: 1.09–3.12]), pulmonary valve atresia without ventricular septal defect (VSD) (HR: 2.60 [95% CI: 1.32–5.12]), VSD (HR: 1.56 [95% CI: 1.19–2.03]), and atrial septal defect (HR: 1.34 [95% CI: 1.08–1.66]). Hispanic children had higher mortality risk for pulmonary valve atresia without VSD (HR: 1.76 [95% CI: 1.06–2.91]) and hypoplastic left heart syndrome (HR: 1.51 [95% CI: 1.13–2.02]). CONCLUSIONS: We provide evidence that supports racial/ethnic disparities in early childhood mortality among infants with CHDs. Identifying infants with the greatest risk of early childhood mortality will facilitate development of interventions and policies to mitigate these risks.