The purpose of this study was to examine large and small high schools in Virginia to try to understand if the high school student population size influenced the student achievement of eleventh grade students based on identified predictor variables. From the literature review, the main research question, five guiding questions, and a methodology were developed that would best aid in the analysis of the data. Data were collected from the Virginia Department of Education for the 2012-2013 school year that consisted of eleventh grade Virginia Standards of Learning assessments, socioeconomic status, student attendance, minority population, and teacher quality. Hierarchical multiple regression was the statistical method used to analyze the data for the research questions. The results of the study indicate there is a significant relationship between socioeconomic status, student attendance, minority status and student achievement. However, when student population size was introduced, the result for socio-economic status was not significant. The overall conclusion regarding socioeconomic status and student achievement is that the issue is not rooted in the size of a high school population, but in the school as a whole. Overall, results of the study indicate that there is a relationship between a high school student population size and student achievement when statistically controlling for selected variables. From the data derived in this study, students in large high schools academically perform better than small high schools in Virginia when selected variables are controlled.