Background: Routine enquiry about domestic violence during pregnancy is accepted best practice. Training is essential to improve knowledge and practice. Few studies have undertaken a comprehensive evaluation of training impact over time. Aim: To evaluate the longitudinal impact of a domestic violence training and support program to promote midwives’ routine antenatal enquiry for domestic violence using a mixed methods design. Method: Data sources included (1) surveys of midwives at 6 months post-training, (2) interviews with key stakeholders at 12 months, (3) chart audit data of screening, risk, and disclosure rates (for 16 months). Measures included midwives’ knowledge, preparation for routine enquiry, knowledge of domestic violence and perceptions of impact of the training and support for practice change. Findings: Forty (out of 83) participant surveys could be matched and responses compared to baseline and post-training scores. Wilcoxon signed-rank test identified that all 6-month follow-up scores were significantly higher than those at baseline. Level of preparedness increased from 42.3 to 51.05 (Z = 4.88, p < .001); and knowledge scores increased from a mean of 21.15 to 24.65 (Z = 4.9, p < .001). Most participants (>90%) reported improved confidence to undertake routine inquiry. A chart audit of screening rates revealed that of the 6671 women presenting for antenatal care, nearly 90% were screened. Disclosure of domestic violence was low (<2%) with most women at risk or experiencing violence declining referral. Conclusions: Training, support processes, and referral pathways, contributed to midwives’ sustained preparedness and knowledge to conduct routine enquiry and support women disclosing domestic violence.