This paper on at-risk students in high schools examines and summarizes the literature on characteristics of youth-at-risk, factors causing at-risk students to drop out, and effective methods for keeping at-risk students in school. Those students who are most at-risk have the following characteristics: poor academic record; low parental education level; dislike for school; little or no participation in extra-curricular activities; discipline problems; disrupted home life; low socioeconomic status; age of 16 or 17 years in grades 9 through 11; poor self-concept; inadequate goals; low aspirations; and poor reading ability. Literature related to each of these characteristics is summarily reviewed. Also discussed are reasons why at-risk teens drop out of school. These include academic failure; marriage, marriage plans, or pregnancy; dislike or lack of interest in school; discipline problems; and inability to get along with teachers or peers. The concluding section discusses 10 characteristics of successful drop-out intervention programs. These include systematic identification of at-risk youth, appropriate program organization, proper staff selection, team approach, unique or specific focus to the educational process, careful student selection, respected institutional role, administrator flexibility, community involvement, and substance abuse awareness. (RH)