This study investigated high school students' and teachers' perceptions of academic self perception, environmental perceptions, goal valuation, and motivation/self-regulation as factors affecting students' academic achievement. A two-way MANOVA was conducted to determine if high school students' gender and academic programs, Non-Honors/Non-Advanced Placement (AP) and Honors/Advanced Placement (AP), differed in their perceptions of academic self perception, attitudes towards teachers and classes, attitudes towards school, goal valuation, and motivation/self-regulation using the "School Attitude Assessment Survey-Revised." Students in the Honors/AP program had higher levels of academic self-perception and motivation/self-regulation than Non-Honors/Non-AP students' results. Females had higher levels of motivation/self-regulation than males while males possessed greater attitudes towards school results. A stepwise multilinear regression was conducted to determine if gender, academic self-perception, attitudes towards teachers and classes, attitudes towards school, and motivation/self-regulation were predictors of students' academic achievement as indicated by their self-reported grade point average (GPA). High school students' academic self-perception and motivation/self-regulation were significant predictors of their academic achievement results. A one-way MANOVA was conducted using data from the "Student Achievement Inventory: Teacher Form" to determine if high school teachers' perceptions of their students' levels of academic self-efficacy, goal valuation, environmental perceptions, and motivation/self-regulation as factors affecting their academic achievement varied according to teacher experience. No statistical differences existed between the teachers' level experience, as determined by their years spent teaching, and their perceptions of their students' levels of academic self-efficacy, goal valuation, environmental perceptions, and motivation/self-regulation as factors affecting academic achievement. This study also sought to identify the students' and teachers' perceptions of factors impacting high school students' underachievement and to determine possible solutions to support students' their achievement. A general qualitative study consisting of high school teachers and their students was conducted using "High School Students' Views on Doing Well in School" and "High School Teachers' Views on Doing Well in School" surveys to determine causes of and solutions to underachievement. An interpretational analysis of the data revealed the emergence of environmental factors affecting student achievement, motivation, student attendance, students' behaviors and skills, and support services and strategies as core categories affecting high school students' academic achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]