The effects of participation in the Chicago (Illinois) Child-Parent Center and Expansion Program from ages 3 to 9 on early school dropout at age 17 were studied. The Child-Parent Centers offer a government-funded educational intervention program in preschool through second or third grade in 20 locations in Chicago's poorest neighborhoods. Using data from the Chicago Longitudinal Study, two major questions are addressed: (1) Is participation in the Child-Parent Centers program associated with a lower rate of school dropout at age 17?; and (2) Which nonintervention variables predict high school dropout? After comparing 20 children in intervention sites with similar children who attended schools in similarly poor neighborhoods in which the intervention program was not offered, it was found that participation in the intervention offered by the Child-Parent Centers is associated with a 7 or 8 percentage point reduction in the probability of dropout. Findings also indicate that parental involvement in schooling and avoidance of frequent school mobility are important predictors of high school completion. An appendix contains a table of estimated effects of participation. (Contains 7 tables and 23 references.) (SLD)