Findings of a study that determined the influence of parental involvement on eighth-grade students' achievement are presented in this paper, which examined the following specific components of parent involvement: aspirations, home structure, discipline, and school activity participation. Data on 21,835 students and their parents were derived from the National Education Longitudinal Study of 1988 (NELS). Latent variable structural equations analysis (LISREL) was used to determine the effects of parental involvement on student achievement, to compare the effects of various components of parental involvement, and to compare the effects of students' versus parents' perceptions of involvement. Findings indicate that parental involvement in their children's homework had a substantial effect on achievement test scores and that the extent of television viewing had no effect. Parental educational aspirations had a positive effect on overall achievement, and family structure had a small negative effect. Students' perceptions of parental involvement were more important than were parents' reports of participation. Eleven figures are included. (8 references) (LMI)