The data include three types of dropout rates. The event rate represents the share of students who leave school without completing high school during a single year. The status dropout rate represents the proportion of individuals at any given point in time who are not enrolled in school and have not finished high school. The cohort rate considers what happens to a single group of students as they pass through school. Findings showed that from October 1985 through October 1988 the average event dropout rate has been 4.4 percent for students in grades 10-12. The status and cohort rates are higher because they reflect the cumulative impact of dropout events from all grades over a number of years. Several demographic, socioeconomic, and behavioral characteristics are associated with dropping out. Results indicate that the dropout problem is substantial, although dropout rates have been falling for the past 10 years. Furthermore, many dropouts complete high school in some manner within a few years after dropping out, although it is not yet clear whether the way a student completes school makes a difference in terms of skills attained, further education pursued, or success in the labor market. Tables and appended tables and methodological information.