The education system in any society has numerous functions, one of which is the effort to realize and strengthen national identity. This research aims to represent and analyse teachers' lived experiences of how national identity is institutionalized in elementary school students. The design of this research is qualitative and uses a phenomenological method. Data was collected using semi-structured interviews. The participants in this study were eight elementary school teachers in Tehran who were selected through purposive sampling and the interviews continued until theoretical saturation was reached. The interviews were analysed using the Colaizzi model. By analysing the teachers' lived experiences of how national identity is institutionalized in elementary school students, 29 basic themes were initially identified and categorized. These basic themes were then grouped into a more general category of first organizing themes (cultural, historical, geographical, educational, religious, Persian language and literature, and social dimensions). Based on the study of identity in this study and an in-depth analysis of teachers' lived experiences, various factors influence the institutionalization of students' national identity, some of which include creating measures to prevent absorption into a foreign culture, familiarity and creating a sense of belonging to the country's history, attention to innovation and creativity in strengthening national identity, attention to teaching commitment and conscientiousness, the need to pay attention to the attractive presentation of Persian culture and literature, cooperation and participation of other social institutions, and the influence of the media.