A recent report on the impact of dual enrollment programs noted that "despite the popularity and growth of dual enrollment programs, little is known about their efficacy" (Karp, Calcagno, Hughes, Jeong, & Bailey, 2007). Furthermore, much of what is known tends to focus on "postsecondary"--full-time as opposed to part-time college enrollment, college enrollment persistence, college GPAs, and college credit earned--rather than "secondary" school effects. Regional Educational Laboratory Southeast (REL-SE) staff did identify several studies, though, that examined secondary school outcomes for dual enrollment students. In general, the studies concluded that dual enrollment students: outperformed district averages on statewide math and ELA assessments; graduated from high school with approximately one year's worth of college credit; and were more likely to graduate from high school and to enroll in college than their non-dual enrollment counterparts. The reports are summarized in a table. An annotated bibliography on dual enrollment and secondary school success is included.