In recent years the numbers of immigrants attending maternity hospitals has risen. The amount of antenatal care these women receive varies widely. Analysis was performed of deliveries to immigrant women in the Rotunda Hospital in 2002. Women were sub-divided depending on antenatal care received in Ireland. Women who received no antenatal care were 'unbooked', those who attended the hospital two to 28 days before delivery were 'late bookers'. The remaining women were 'booked'. There were 1,954 deliveries to immigrant women; 1,1 73 (60%) 'booked', 391 (20%) 'late bookers' and 390 (20%) 'unbooked'. 'Unbooked' women had a higher rate of spontaneous vertex delivery (63%) (p < 0.01). 'Late bookers' had a higher rate of caesarean section (27.6%) (p < 0.01). The 'late bookers' infants were more likely to be preterm, low birth weight and had a higher rate of neonatal ICU (NICU) admissions (p < 0.01). This study has identified 'late booker' immigrants as a high-risk group.