Introduction: Clinical education is the core component of nursing education. PhD graduated nurses who are faculty members can play a main role in clinical instruction. However, there is not clear understanding about the challenges which they may encounter for accepting their role as clinical educator. The aim of this study was to explore the challenges of role acceptance by PhD aduated nurses who are faculty members. Methods: In this qualitative exploratory study a total of 13 participants (8 PhD graduated in nursing, 3 head of departments of nursing, one educational vice chancellor of nursing school, and one nurse) were selected by purposive sampling method. Data were collected by semi-structured, face to face interview and analyzed by conventional content analysis approach developed by Graneheim and Lundman. Results: The main theme emerged from data analysis was "identity threat". This theme had five categories including expectations beyond ability, lack of staff’s rely on the performance of PhD graduated nurses, poor clinical competencies, doubtfulness, and obligation. Conclusion: PhD graduated nurses experienced some worries about their role as clinical educators and argued that they have not been prepared for their role. Therefore, policy makers and authorities of nursing schools should support PhD graduated nurses for accepting their new roles as clinical educators. Moreover, some changes in nursing PhD curriculum is needed to improve the clinical competencies of PhD graduated and prepare them for their role as a clinical educator.