Private school enrollment has steadily declined over the last 15 years (Kena et al., 2016). Enrollment decline has closed many private schools and threatens the sustainability of many more (Hunt, McGovern, & Taylor, 2016; Wiens & Wiens, 2012). Many factors may lead to a family choosing to leave a school (Ewert, 2013). Some factors are outside the control of the school, but schools must quickly address any factors that are within their control. School retention literature has identified the importance of the faculty-student relationship, the presence of academic rigor, a safe learning environment, and a strong school community in the retention process (Ahlstrom, 2013; Davis & Cole-Leffel, 2009; Hansen & Toso, 2007; Tinto, 1975). These factors could be addressed individually to influence student retention or school leaders can focus their attention on improving the school's culture, which in turn will have a positive influence on all areas of the school including retention. This study examined private school enrollment decline and the relationship between student retention and school culture. Thirty-one private schools from 17 states participated in this study. S. Gruenert's (2005) School Culture Survey (SCS) was used to measure collaborative school culture at each of the participating schools; this data was analyzed with the self-reported retention data from each school. The study found a positive relationship between school culture and student retention. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]