Background: The journey to nursing professionalism is a constantly progressing process. The present study aimed to explain the experiences of nursing students and faculty members regarding the unseen consequences of the hidden curriculum for nursing professionalism. Methods: In this qualitative study, 25 nursing students and faculty members at Mashhad University of Medical Sciences were selected and interviewed based on purposive sampling. After data collection, all the recorded interviews were transcribed and reviewed, and their subcategories, categories, and themes were extracted using the qualitative content analysis approach proposed by Graneheim and Lundman. Results: A total of 1382 initial codes and two main themes were extracted from the interviews. The obtained categories were non-constructive and destructive clinical environment, unfavorable educational environment, the gap between theory and practice, inappropriate role model, neglect of scientific nursing knowledge, loss of professional values, undervaluing nursing professionalism, favorable clinical environment, favorable faculty environment, and faculty member as an effective role model. Conclusion: Professional behaviors have significant impacts on professionalism in nursing. There is a significant gap between the current nursing practice and professional nursing in some aspects. Therefore, it is important to consider all consequences of the hidden curriculum to achieve professionalism.