This study evaluated an intervention for low-income new mothers, half from Spanish-speaking homes, that provides education around infant crying and abusive head trauma (AHT). At enrollment, non-US-born mothers were less likely than US-born mothers to have heard of shaken baby syndrome (60% vs 89%, P ≤ .0001) or to know shaking babies could lead to brain damage or death (48% vs 80%, P < .0001). At follow-up, non-US-born intervention mothers had improved knowledge of the peak of crying (31% vs 4%, P = .009), improved knowledge that shaking a baby could lead to brain damage or death (36% vs 12%, P = .035), and identified more calming strategies for parenting stress compared with non-US-born control mothers (+0.8 [SD = 1.1] vs -0.4 [SD = 1.4]). This study identifies a gap in AHT knowledge at baseline of non-US-born mothers. These mothers had improved knowledge with intervention and are an important population for similar prevention efforts.