Objectives: To describe the characteristics of immigrant women's newborns in our environment, and to compare them with those of native women's newborns. Patients and methods: All newborns attended in the Neonatology Section of Hospital del Mar in Barcelona, Spain, in 2003 and 2004 were included (n = 2,735). Data were prospectively collected in a database. Pregnant immigrant women were classified in 6 regions (Eastern Europe, the rest of Europe, Africa, Asia, Latin America and other countries). Twelve diagnoses were defined and compared between native newborns and those of immigrant parents, and their relative risks were calculated. Results: There were 1,296 native newborns (47.8%) and 1,416 of immigrant origin (52.2%). Immigrant women showed a higher rate of HBsAg carrier status (2.0% versus 1.0%) and a lower rate of hepatitis C virus infection (0.8% vs 2.0%; p < 0.01). There was only one HIV-positive pregnant immigrant woman compared with 14 Spanish women (p < 0.01), and drug use was lower in the immigrant group (0.4% vs 4.0%; p < 0.01). Immigrant newborns had a lower rate of prematurity (6.0% vs 7.6%) and of low birthweight (2.3% vs 4.6%; p < 0.01). There were no significant differences in the rate of respiratory distress or fetal acidosis. The incidence of neonatal infection risk was higher in immigrant newborns (49.9% vs 40.6%; p < 0.01). Conclusions: In our environment, immigrant mothers' newborns have better perinatal outcomes than native newborns. The most frequent complications are secondary to an inadequate.