Improving instruction, improving student education and improving the performance of standardized assessment requires attention to many aspects within the school environment. The purpose of the study was to explore the student-teacher ratio and in school/out of school suspensions in southeast Missouri school districts. The study also examined whether a difference exists between elementary, middle school and high school concerning student-teacher ratio and in school/out of school suspensions in southeast Missouri. The following research questions were examined: (1) What is the relationship between student-teacher ratio and the in school suspension rate of southeast Missouri schools? (2) What is the relationship between student-teacher ratio and out-of-school suspension rate of southeast Missouri schools? and (3) How do variables such as building level, free and reduced lunch membership and ethnicity affect the relationship between student-teacher ratio and in/out of school suspension rates in southeast Missouri schools? The research hypothesis for the study can be stated as follows: (H1) The number of in school suspensions will be lower in reduced size classrooms in southeast Missouri schools. (H2) The number of out of school suspensions will be lower in reduced size classrooms in southeast Missouri schools. A regression analysis was used to answer the research questions from school district data reported to the Missouri Department of Elementary and Secondary Education (DESE). The analyzed data from school years 2013 through 2015 was retrieved from the DESE website and is in the public domain. The findings revealed that the percentage white and middle school enrollment had an impact on in school suspension rates and the percentage white population, middle school and high school levels had an impact on out of school suspension rates; however, there was no relationship between classroom size and the suspension rate. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]