The need for more diversity in STEM-related careers and college majors is urgent. Self-efficacy and student-teacher relationships are factors that have been linked to influencing students' pursuit of subject-specific careers and academic achievement. The impact of self-efficacy and student perceptions of teacher interpersonal behaviors on student achievement have been extensively researched in the areas of Mathematics and English, however, most studies using science achievement, as a criterion variable, were conducted using non-diverse, White upper middle class to affluent participants. In order to determine the strength of relationships between perceived science self-efficacy, and student perceptions of teacher interpersonal behaviors as factors that influence science achievement (science GPA), the Science Self-Efficacy Questionnaire (SSEQ) and Questionnaire on Teacher Interactions (QTI) were administered to twelfth grade students enrolled at a highly diverse urban Title I high school, while controlling for demographics, defined as gender, ethnicity, and minority status. Using a hierarchical multiple linear regression analysis, results demonstrated that the predictor variables (i.e., gender, ethnicity, minority status, science self-efficacy, and teacher interpersonal behaviors) accounted for 20.8% of the variance in science GPAs. Science self-efficacy made the strongest unique contribution to explaining science GPA, while minority status and gender were found to be statistically significant contributors to the full model as well. Ethnicity and teacher interpersonal behaviors did not make a statistically significant contribution to the variance in science GPA, and accounted for = 1% of the variance. Implications and recommendations for future research are subsequently given. [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.]