This study examined differences in perinatal outcomes of Southeast Asian (SEA) women compared with non-Hispanic white women in Washington. Using linked birth certificate and hospitalization discharge records for the years 1993-2006, we compared singleton births of Cambodian (3,858), Laotian (2,223), and Vietnamese (12,949) women with a random sample of white women (35,581). Associations between maternal nativity and perinatal outcomes were assessed using multivariable logistic regression. There are clear nativity differences among SEAs for gestational diabetes mellitus, anemia, placenta previa and febrile illness. SEAs had increased risks for these disorders when compared with white women. Compared with infants delivered of white women, infants of SEAs had increased risks for moderate to heavy meconium, birth injury and low birth weight. Differences in nativity among SEAs (populations that are traditionally studied in aggregate) should be considered when designing and carrying out interventions to prevent adverse pregnancy morbidity and outcomes among immigrants.