Both descriptive and multivariate statistics were employed in the analyses. The average dropout rate for the cohort as a whole was 13.6 percent. Students with the least favorable socioeconomic and other family background characteristics -- those with parents in low-level jobs, with parents who are relatively uneducated, who come from single-parent homes and large families -- were three to five times more likely to drop out than students from more advantaged backgrounds. There was some evidence that females were most sensitive and black males were least sensitive to these factors. Other things being equal, drop-out rates were generally higher in the South and West than in the Northeast and Central regions and in urban than in rural or suburban areas. Of school variables, only school size and teacher turnover rates showed significant effects on drop-out rates. Working while in school, marrying and having children, and behaving antisocially in or out of school (disciplinary problems, suspension, probation, trouble with the law) also were related to increased risk of dropping out. The relationship between antisocial behaviors and failing to graduate was large and consistent across ethnic and gender groups and persisted even when many student background and school factors were held constant. 20 tables and 44 references.