Research has indicated that developmentally appropriate practices (DAP) should be applied to manage behavioral problems in school age children. However, little evidence exists on the extent to which elementary school principals apply these practices appropriately in student discipline. The purpose of this phenomenological study was to explore how 10 elementary principals perceived DAP and to discover the meaning they ascribed to their experiences and discipline practices. The theories of Piaget and Erikson provided a basis for understanding the growth and developmental changes of school age children occurring during the early years. The research questions examined the perceptions of elementary principals and their practices related to DAP in student discipline. Data collection consisted of interviews, principals' electronic journaling, and questionnaires. Data were analyzed using open coding and categorizing to reveal patterns and themes. Several patterns and themes emerged. All principals were cognizant of the importance of their administrative practices in creating a positive climate for orderliness, safety, and learning. However, their responses signaled that discipline practices were not uniformly applied in elementary schools. Discipline policies of school districts and student discipline codes often governed their disciplinary practices. Warnings, both written and verbal, were most prevalent in student discipline. The findings underscored the need for elementary principals to reassess and evaluate their disciplinary procedures for young children. This study positively impacts change by providing school leaders with positive insights of DAP to ensure age appropriate and constructive disciplinary practices are used to promote positive school behaviors in young children. [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.]