The Counties Manukau DHB (CMDHB) in South Auckland serves the most economically deprived areas of New Zealand, with a high proportion of young mothers, and women of Māori and Pacific ethnicity. CMDHB has high rates of late booking for antenatal care and also the highest perinatal mortality rate in New Zealand, with a 3-year perinatal-related mortality rate of 13.70 per 1000 births compared with the national rate of 10.75 per 1000 births. This study aimed to identify barriers to early initiation of antenatal care (before 19 weeks of pregnancy) among women using CMDHB maternity services. The study recruited 826 pregnant women who were either in late pregnancy (>37 weeks gestation) or who had recently delivered (<6 weeks postnatal). They completed a questionnaire about their antenatal care at CMDHB. 137 women (17%) booked for antenatal care at >18 weeks (late bookers). Ethnic groupings were 43% Pacific Peoples, 20% Māori, 14% Asian, and 21% European or other ethnicities. According to multivariate analysis, women were significantly more likely to book late for antenatal care if they had limited resources (e.g. no transport) (OR 1.86), no tertiary education (OR 1.96), or were not living with a husband/ partner (OR 2.34). Notably, the odds of late booking for antenatal care was almost 6 times higher among Māori (OR 5.70) and Pacific (OR 5.90) women compared to those of European and other ethnicities.