Nursing errors can cause irreparable consequences. Understanding the concept of error and the nature of nursing error detectors can significantly reduce this type of errors. The present study was conducted to explain the concept of error and the nature of nursing error detectors in military hospitals.The present study was conducted on eight nurses working in different wards of military hospitals using a qualitative approach to content analysis proposed by Graneheim and Lundman. Data were collected through in-depth semistructured interviews.'The concept of error' and 'the nature of error detectors' in military hospitals were the two main categories extracted from data analysis. The present findings showed that the nature of errors in military hospitals is inevitable, a threat to job position and bipolar. Nurses use different resources to identify errors, including personal, environmental and organisational factors of detection.Given the military nature of the study hospitals, organisational factors of detection played a key role in identifying errors. Moreover, given the perception of military nurses of errors, they were not inclined to personal detectors. The managers of military hospitals are therefore recommended to pursue a justice-oriented and supportive culture to help nurses play a more active role in identifying errors.