Objectives. We investigated how state-level firearms legislation is associated with firearm ownership and storage among families with preschool-aged children. Methods. Using 2005 nationally representative data from the Early Childhood Longitudinal Study-Birth Cohort (n = 8100), we conducted multinomial regression models to examine the associations between state-level firearms legislation generally, child access prevention (CAP) firearms legislation specifically, and parental firearm ownership and storage safety practices. Results. Overall, 8% of families with children aged 4 years living in states with stronger firearm laws and CAP laws owned firearms compared with 24% of families in states with weaker firearm laws and no CAP laws. Storage behaviors of firearm owners differed minimally across legislative contexts. When we controlled for family- and state-level characteristics, we found that firearm legislation and CAP laws interacted to predict ownership and storage behaviors, with unsafe storage least likely among families in states with both CAP laws and stronger firearm legislation. Conclusions. Broader firearm legislation is linked with the efficacy of child-specific legislation in promoting responsible firearm ownership.