This report summarizes characteristics of students with disabilities in the National Education Longitudinal Study (nels:88), which conducted a base-year survey in 1988 of all U.S. public and private schools containing eighth grades, followed up at 2-year intervals in 1990, 1992, and 1994. Among general observations are the following: (1) students identified in nels:88 as disabled tended to have greater difficulties in school and realized fewer positive outcomes of schooling; (2) relatively small percentages of students with disabilities as identified by nels:88 perceived themselves or were identified by school officials as having received special education services during high school; and (3) teachers in nels:88 were perceptive judges of which students were failing to perform well in the classroom, but linking the identification of disability status to classroom performance may blur the distinction between students with disabilities and students at risk. After an introductory chapter, individual chapters address the following issues concerning students with disabilities: disability identification, students' background characteristics, school experiences, and educational outcomes. A concluding chapter lists characteristics of populations identified as disabled by both parents and teachers and only by teachers, not by parents. Four appendices list nels:88 indicators of disability, nels:88 disability estimates based on alternative disability definitions, and research/technical notes. (Contains 12 references.) (Db).