The positive deviance approach identifies and promotes existing uncommon healthy behaviours. A positive deviance-informed antenatal project was pilot-tested in Al-Minia Governorate, Upper Egypt, during 2003-2004, after a positive deviance study in 2000 found that successful pregnancies had increased consumption of meat and vegetables, daytime rest, and antenatal care; less second-hand smoke exposure; and symptoms of no urinary tract infection. Accordingly, health facilities were upgraded in target and comparison areas to provide quality antenatal care, including treatment of urinary tract infection. Additionally, in the target villages, women at-risk of delivering low-birth-weight infants were enrolled in weekly 'IMPRESS' (improved pregnancy through education and supplementation) sessions with counselling and supplemental food. In total, 519 women (344 target, 175 comparison) were enrolled in the third or fourth month of pregnancy and were followed through delivery. Birth-weights of the target mothers increased 2.2 times more than birth-weights of the comparison mothers over baseline (mean increase: 0.58 vs 0.26 g respectively, p<0.01). Similarly, the decrease in prevalence of low birth-weight from baseline was greater in the target villages than in the comparison mothers (% of decrease: 26.9 vs 11.9 respectively, p<0.01). The target at-risk women were far more likely than their counterparts to report eating more food (54.9% vs 10.6%), more meat (57.1% vs 4.2%), more vegetables (66.9% vs 5.3%), increasing daytime rest (64.1% vs 11.7%), and avoiding second-hand smoke (91.3% vs 51.6%) during pregnancy. The cost per 100 g of improvement in birth-weight was US$ 3.98. The Government of Egypt and partners are scaling up the elements of the project.