Background: Intimate partner abuse is a major contributor to death, disability, and illness in women of childbearing age, but little is known about population level impact on children. Method: Prospective pregnancy cohort of 1,507 first-time mothers recruited from six public hospitals in Melbourne, Australia. Follow-up included validated measures of intimate partner abuse at 1 and 4 years (Composite Abuse Scale) and child emotional and behavioral difficulties at 4 years (Strengths and Difficulties Questionnaire). Results: Twenty-nine percent of mothers reported partner abuse in the first 4 years postpartum: 20 percent reported abuse in the first year and 21 percent at 4 years; 12 percent of mothers reported abuse at both time points. Children of mothers reporting abuse at both times were more likely to experience emotional and/or behavioral difficulties at age 4, compared to children of mothers not reporting abuse, after adjusting for maternal depressive symptoms, relationship transitions and other social characteristics (Adj. OR 2.6 [95% CI 1.2-5.5]). Conclusions: Intimate partner abuse impacted the lives of one in four children. Children of mothers reporting abuse at both time points were at most risk of emotional/behavioral difficulties. The case for early intervention to reduce the impact of intimate partner abuse on women’s and children’s lives is compelling.