Few studies have examined the effects of household change on adolescent development. We study household composition change and its effect on development, as measured by both internalizing symptoms and externalizing behaviors, in a sample of urban African American adolescents. Household change was defined based on the movement in or out of the household of one of the 2 most important adults adolescents named. We found 25% of adolescents reported changes in their household composition over the 4 years of high school. Youth who experienced change reported more internalizing symptoms and externalizing behavior than youth who did not experience change. Those reporting important people leaving their household had the greatest negative outcomes. (Contains 3 tables.)