Almost 19,000 Dade County Public School students--all the members of the 8th grade cohort in June 1980--were followed across four and a half years in a study of dropouts. Major findings include the following: (1) at the end of the follow-up period, 29.5% of the cohort had dropped out (19% of Asians, 26.4% of Whites, 29.3% of Hispanics, and 33.9% of Blacks; 26.8% of females and 32.1% of males); (2) almost 60% of the dropping out took place in the first two years of the follow-up; (3) compared to Whites and Hispanics, Blacks were more likely to drop out late in the follow-up period; (4) the dropout rate for Cuban-born Hispanics was 30% versus 28.8% for all other Hispanic students (the rate for pre-Mariel Cubans was 29.9%, for post-Mariel Cubans 33%); (5) the dropout rate for Haitian-born students was 38.8%, the highest of any group; (6) the dropout rate for exceptional (but not including gifted) students was higher than the regular student rate; and (7) students who were not out of phase (i.e. had not been kept back) by 8th grade were equally likely to drop out regardless of ethnic group, and were less than half as likely to drop out as students who were out of phase by that time. (The longitudinal method of calculating dropout rate used in this study is described and contrasted with the cross-sectional method in an appendix.) (CMG)