The number of foreign migrants tends to grow. The situation of people living away from their own country is complex and has an impact on the public health system. The objective of this article was to analyze the perinatal risk of migrant mothers and their newborn infants in comparison to native Argentine mothers and their newborn infants.Cohort study that included 2000 mothers and their newborn infants (1000 migrants and 1000 natives) assisted at a public maternity hospital.Native mothers had a higher rate of low birth weight newborn infants (9.9% versus 5.3%; p <0.01), primiparity (42% versus 37%; p= 0.012), and adolescent pregnancy (6% versus 1.3%; p <0.001). Migrant women had a higher rate of poorly controlled pregnancies (21.7% versus 13.4%; p <0.01), positive serology for Chagas disease (3.2% versus 0.4%; p <0.01), and newborn infants requiring phototherapy (20.5% versus 14.3%; p =0.04).In our study, Argentine mothers had a higher rate of low birth weight newborn infants, primiparity and adolescent pregnancies, while immigrant women had higher rate of positive serology for Chagas disease, poor antenatal controls and more newborn infants requiring phototherapy.