Recognizing the potential of classrooms as a context for identifying and addressing child victimization, several U.S. states now mandate the inclusion of child abuse prevention in school curricula. There are, however, a limited number of evidence-based and developmentally appropriate curricula designed for elementary. This study utilized a randomized control trial (RCT) design to evaluate the knowledge acquisition of children who received the Monique Burr Foundation's Child Safety Matters curriculum, a program designed to educate kindergarten to Grade 5 children about bullying, cyberbullying, four types of abuse (physical, sexual, emotional, and neglect), and digital dangers. Participants included 1,176 students from 72 classrooms in 12 Florida schools across eight counties. Schools were matched in pairs and randomly assigned to receive the program or be in a wait-list control. Knowledge was assessed with a questionnaire administered prior to the curriculum (T1) as well as approximately 3 weeks (T2) and approximately 7 months (T3) after implementation. Analyses were conducted with class means examining grade, treatment condition, and time. The interaction of treatment and time was significant, F(2, 90) = 17.024, p < .000. Children who received the curriculum increased their knowledge about potentially risky situations, and this knowledge was sustained over 7 months to the follow-up assessment. Children in the control schools did not have similar gains. The current classroom-based child maltreatment prevention education is a promising strategy to address children's vulnerability to abuse and its consequences.