Moral intelligence is one of the dimensions of intelligence that can provide a framework for the proper function of man, and be used as a predictor for people's conduct. Nurses' performance is of great importance because of the moral and human nature of their profession, and their adherence to ethical principles improves the nursing care quality as well as organizational performance. Therefore, the present study aimed to assess moral intelligence in nurses. This cross-sectional study was conducted on 400 nurses from teaching hospitals in South Khorasan. Participants were selected through census method. Data were collected by Lennik & Kiel's moral intelligence questionnaire, and data analysis was performed using SPSS 16 software and descriptive and analytical statistics tests. The results suggest that the nurses' moral intelligence score was 4.35±0.56 (range: 1-5). There was a direct and meaningful relationship between moral intelligence and age and years of practice (P < 0.05). Optimal levels of moral intelligence suggest the importance that nurses attribute to moral values, and can also be an indirect manifestation of their moral conduct in healthcare environments.