Introduction : Do Not Resuscitate (DNR) order has been studied ethically, legally, and religiously in different countries after presentation by the American Medical Association (AMA) in 1974. This study was conducted to investigate the attitude of nurses in intensive care units (ICUs) of hospitals of Tabriz University of Medical Sciences, Tabriz, Iran, towards DNR order. Methods: 255 nurses working in ICUs were included in a descriptive-analytical study at Tabriz University of Medical Sciences in 2018. The utilized checklist contained two sections: demographic information and 11 questions with a 5-point Likert scale about the attitude towards the DNR order. The scores relating to each question were collected and analyzed. Results: The average of the total score of the questionnaire was 29.97 8.39. The attitudes of participants were negative in all questions except for the 8th and 11th questions. The total score of the questionnaire was 29.49 8.09 in the group with work experience of 15 years and less and 32.49 9.50 (P = 0.036) in the group with a more than 15 years of work experience; which indicates more positive attitude towards the DNR order in individuals with more work experience. Conclusion: The results showed that in general, the participant nurses did not have positive attitudes concerning the DNR order; however, people with more than 15 years of work experience had more positive attitude towards this order and the investigation of this factor and the causes of its impact on the change of people’s attitude should be carried out in further studies.