Objectives: To evaluate the effect of targeted and catch-up hepatitis B virus (HBV) vaccination programs in New South Wales on HBV prevalence among women giving birth for the first time. Design: Observational study linking data from the NSW Perinatal Data Collection for women giving birth during 2000e2012 with HBV notifications in the NSW Notifiable Conditions Information Management System. Main outcome measures: HBV prevalence in Indigenous Australian, non-Indigenous Australian-born, and overseas-born women giving birth. Results: Of 482 944 women who gave birth to their first child, 3383 (0.70%) were linked to an HBV notification. HBV prevalence was 1.95% (95% CI, 1.88e2.02%) among overseas born women, 0.79% (95% CI, 0.63e0.95%) among Indigenous Australian women, and 0.11% (95% CI, 0.09e0.12%) among non-Indigenous Australian-born women. In Indigenous Australian women, prevalence was significantly lower for those who had been eligible for inclusion in the targeted at-risk newborn or universal school-based vaccination programs (maternal year of birth, 1992e1999: 0.15%) than for those who were not (born ≤ 1981: 1.31%; for trend, P < 0.001). There was no statistically significant downward trend among non-Indigenous Australian-born or overseas-born women. HBV prevalence was higher among Indigenous women residing in regional and remote areas than those in major cities (adjusted odds ratio [aOR], 2.23; 95% CI, 1.40e3.57), but lower for non-Indigenous (aOR, 0.39; 95% CI, 0.28e0.55) and overseas-born women (aOR, 0.61; 95% CI, 0.49e0.77). Conclusion: Among women giving birth, there was a significant reduction in HBV prevalence in Indigenous women associated with the introduction of the HBV vaccination program in NSW, although prevalence remains higher than among non-Indigenous Australian-born women, and it also varies by region of residence. Continuing evaluation is needed to ensure that the prevalence of HBV infections continues to fall in Australia.