Objective. The goal was to examine the association between early childhood neglect (birth to age 2 years) and later childhood aggression at ages 4, 6, and 8 years, compared with aggression's associations with early childhood abuse and later abuse and neglect. Methods. A prospective cohort of 1318 predominantly at-risk children, recruited from 4 US cities and 1 southern state, were monitored from birth to 8 years of age. Maltreatment was determined through review of local child protective services records. A hierarchical, linear model approach, a special case of general, linear, mixed modeling, was used to predict aggressive behavior scores, as reported by the child's primary caregiver at ages 4, 6, and 8 years. Results. Only early neglect significantly predicted aggression scores. Early abuse, later abuse, and later neglect were not significantly predictive in a controlled model with all 4 predictors. Coclusion. This longitudinal study suggests that child neglect in the first 2 years of life may be a more-important precursor of childhood aggression than later neglect or physical abuse at any age. Copyright 2008 by the American Academy ofPediatrics.