Background: Ninety-nine percent of the 4 million neonatal deaths per year occur in developing countries. The World Health Organization (WHO) Essential Newborn Care (ENC) course sets the minimum accepted standard for training midwives on aspects of infant care (neonatal resuscitation, breastfeeding, kangaroo care, small baby care, and thermoregulation), many of which are provided by the mother. Objective: The aim of this study was to determine the association of ENC with all-cause 7-day (early) neonatal mortality among infants of less educated mothers compared with those of mothers with more education. Methods: Protocol- and ENC-certified research nurses trained all 123 college-educated midwives from 18 low-risk, first-level urban community health centers (Zambia) in data collection (1 week) and ENC (1 week) as part of a controlled study to test the clinical impact of ENC implementation. The mothers were categorized into 2 groups, those who had completed 7 years of school education (primary education) and those with 8 or more years of education. Results: ENC training is associated with decreases in early neonatal mortality; rates decreased from 11.2 per 1000 live births pre-ENC to 6.2 per 1000 following ENC implementation (P < .001). Prenatal care, birth weight, race, and gender did not differ between the groups. Mortality for infants of mothers with 7 years of education decreased from 12.4 to 6.0 per 1000 (P < .0001) but did not change significantly for those with 8 or more years of education (8.7 to 6.3 per 1000, P = .14). Conclusions: ENC training decreases early neonatal mortality, and the impact is larger in infants of mothers without secondary education. The impact of ENC may be optimized by training health care workers who treat women with less formal education. © 2008 Academic Pediatric Association.