This report describes career academies in 12 Florida school districts in the 2006/07 school year. It examines their structure and career clusters, the high schools offering them, and the students enrolled. This study is driven by three research questions: (1) How many career academies were there, and of what types? (2) What were the characteristics of high schools offering career academies? and (3) How many students were enrolled in career academies, and what were their characteristics? This study is one of the first to investigate both career academy structure and clusters using multiple data sources. The findings reveal substantial career academy activity across the 12 Florida school districts in 2006/07. Almost 80 percent of schools had at least one career academy, and there were 596 distinct career academies across the 145 schools offering them. Of those, most operated as school-within-a-school career academies embedded in a larger high school, with most students not participating. Fewer schools reported wall-to-wall academies, where all students participate, and these were primarily in Miami-Dade. Of the 332,010 sample high school students, 49,795 (15 percent) were identified as academy participants. Schools with wall-to-wall academies tended to be larger, and their academies served a more disadvantaged student population (as proxied by the percentage of students eligible for free or reduced-price lunch), on average. Wall-to-wall academies also tended to address more general career clusters, such as arts, audiovisual technology, and communication, and human services. By contrast, school-within-a-school career academies tended to be in smaller schools and serve more advantaged students. School-within-a-school academies also tended to address more specific career clusters, such as hospitality and tourism. (Contains 3 boxes, 4 figures, and 12 tables.)[For "Characteristics of Career Academies in 12 Florida School Districts. Summary. Issues & Answers. REL 2011-No. 106," see ED518374.]