In this interactive session, participants will learn that sibling aggression is the most common form of family violence, but it is often minimized or dismissed. Research findings will be presented on the prevalence of sibling aggression (including variation by socioeconomic status, race, ethnicity, ability, and gender), types of sibling aggression (i.e., physical, property, psychological, sexual), and the associations between sibling aggression and mental and physical health. Participants will learn how to disentangle sibling rivalry from sibling aggression and abuse (SAA). The discussion will be informed by research on perceptions of SAA among practitioners and individuals from diverse cultural backgrounds.