The focus of this quantitative survey study was the examination of the relationship between self-efficacy and academic achievement in 164 at-risk high school students. The study used Bandura's self-efficacy as the theoretical framework. The research questions involved understanding the levels of self-efficacy in at-risk high school students and the relationship between self-efficacy and academic achievement for male and female at-risk high school students. The Multidimensional Scale of Perceived Self-Efficacy was used to measure nine areas of self-efficacy: enlisting social resources, academic achievement, self-regulated learning, leisure-time skill and extracurricular activities, self-regulatory efficacy to resist peer pressure, meet others' expectations, social self-efficacy, self-assertive efficacy, and enlisting parental and community support. The dependent variable, academic achievement, was measured by students' GPA. Pearson correlations were used to test for relationships between GPA and self-efficacy. The relationships between GPA and self-efficacy scores were statistically significant for the following five subscales: social self efficacy, resisting peer pressure, self-assertiveness, academic achievement, and meeting expectations of others. Higher self-efficacy scores were associated with higher GPA for female students only. In general, self-efficacy scores were lowest for enlisting parental or community support, self-regulated learning, and leisure time skills and extracurricular activities. No relationship was found between GPA and self-efficacy for enlisting social resources, leisure-time skills, and extracurricular activities, or enlisting parental and community support. The recommendations of this study include developing self-efficacy of female students and exploring other contributing factors to high academic achievement in at-risk males. Results could be used to prepare at-risk students by creating a learning environment that supports self-efficacy, thereby increasing their chances of academic success. [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.]