Objective: Traumatic stressors, including child abuse and/or interpersonal violence over a woman's lifecourse, can affect the health of her children. This study examines the associations between maternal lifetime interpersonal trauma (IPT) and children's asthma by age 6 years (n = 857). Methods: Pregnant women completed the Revised Conflict Tactics Scale; IPT exposure was categorized as unexposed (55%), early (childhood and/or teen years only, 25%), late (adulthood and/or index pregnancy, 7%), and chronic (early and late, 13%). Clinician-diagnosed asthma in children was reported by mothers at each follow-up visit until the child reached age 6 years. We examined the effects of maternal IPT categories and child's asthma using logistic regression. Using structural equation models, we also examined indirect relationships between maternal chronic IPT and child asthma operating through active asthma in pregnancy, prepregnancy BMI, prenatal smoking, and/or increased exposure to other adverse life events or environmental toxins prenatally. Effect modification by the child's sex was examined. Results: Mothers were primarily Hispanic (55%) or black (30%) with less than high school education (62%). In logistic regression models, chronic maternal IPT (compared with unexposed) was associated with asthma in boys (odds ratio = 2.87, 95% confidence interval = 1.48-5.57) but not girls (odds ratio = 0.69, 95% confidence interval = 0.23-2.12; p(interaction) = .042). In structural equation models, chronic IPT was associated with maternal active asthma in pregnancy (beta = 0.59, p < .001), maternal active asthma was associated with children's asthma (beta = 0.20, p = .009), and the total indirect effect for this path was significant (beta = 0.12, p = .031). Associations were most evident among boys. Conclusions: Mothers' history of chronic IPT was associated with asthma in boys. This association was mediated through active maternal asthma in pregnancy.