Introduction: Nurses are the major group among health care professionals, and so, they must be had accountability in their nursing care delivery. Because, their errors' had effects on patients that it usually they are irreversible. So, legislators for preventing these errors in medical and nursing staff define many penalties, considerably. Aim: the aim of this study was defining negligence concept in nursing care and what it is in Iranian judiciary. Methods and Materials: This study reviewed the laws of Iran such as nemesis and atonements associated about nursing negligence and criminal documents at Criminal Justice Medical Integrated of Tehran and the lawyers' views in 2014. Results: : In Iran, for having taken the nurses accountable in the judiciary system, the behaviors due to their negligence which have led to the patients' deaths or at least their mental and physical damage ought to be taken into consideration and also the secularized causality relationship should be between their behavior and the outcome as well. In the Iranian judiciary system, no definition of nursing negligence or fault has been given by the legislator in the penal system, and only some possibilities such as recklessness, carelessness, lack of skill, and not having regarded the governmental laws and principles have been noticed. Conclusion: It would be suggested that nurse managers planning in-service education and directing nurses with how assessing and reaction of the judiciary systems to nurses' negligence in care delivery.