There is a significant lack of research on the assistant principal position, especially research regarding Missouri secondary assistant principal job satisfaction. As more expectations and responsibilities get pushed on building principals, responsibilities that used to be exclusive to the principalship are now being pushed onto the assistant principal position. Because of this, the assistant principal position is changing and becoming more important, and the job satisfaction of assistant principals is important to be monitored. The aim of this study is to determine if a predictive model can be created to identify what factors most impact Missouri secondary assistant principals job satisfaction. The primary research question is as follows: Using a backward stepwise regression analysis, can predictions be made of assistant principal job satisfaction based on summary statistics and other sets of data? The research question is answered through a non-experimental online survey that was sent to secondary principals and forwarded to assistant principals. Based on the data received from the survey, it could be determined that Missouri secondary assistant principals are largely satisfied with their job and four variables positive impact job satisfaction: the way the assistant principal's boss handles his/her workers, the opportunity for the assistant principal to use his/her abilities, the working conditions, and the sense of accomplishment the assistant principal feels for doing his/her job. Based on this research, assistant principals should receive more praise for the work they do and should be given more opportunities to help lead the school. Further, more research should be focused on the assistant principal position. [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.]