Objective: Smart phones have rapidly become an integral, and for some, an essential communication device worldwide. The issue of identity has always been a subject of interest among psychologists. The present study was conducted to compare personal and national identity and their subscales between cell phone addicts and non-addicts. Method: In this cross-sectional study, 500 student cell phone users from various universities in Tehran were recruited using stratified sampling. Participants completed cell phone addiction questionnaires including Mobile Phone Problematic Use Scale (MPPUS), Cell Phone Dependency Questionnaire (CPDQ), Personal Identity Development Questionnaire, Extended Objective Measure of Ego Identity Status (EOMEIS) and National Identity Questionnaire. Then, the subscales of these instruments were analyzed using SPSS Version 20. Results: Results of this study revealed significant differences between cell phone addicts and non-addicts in the scores of national identity, personal identity, and most subscales, except for some subscales (P<0.05). In addition, a negative and significant relationship was found between personal and national identity and cell phone addiction (r=-0.35, -0.33, respectively).On the other hand, after controlling for the confounder variables, we found that national identity had an effect on cell phone addiction(OR=0.05, CI=0.92-0.98). Conclusion: The results of this study indicated that cell phone overuse may be correlated with defects in some aspects of national and personal identity.