Objective: 1) To study nurses’ opinions on advance directives. 2) To compare nurses’ opinions on advance directives for care of terminal stage among nurses with different proficiency levels.

Material and Method: Two hundred and thirty one professional nurses were selected by simple random technique with constant sampling fraction from each proficiency level. The data collection instrument consisted of 3 parts: a personal data form; a questionnaire on nurses’ opinions on advance directives for care of terminal stage using a rating scale developed by the researcher based on literature review; and open- ended questions on the section 12 of the National Health Act 2550. The reliability of the questionnaire was 0.84. The data was analyzed by chi-square significance indicated by p<0.05.

Results: Nurses’ opinions on the advance directives for care of terminal stage were at a moderate to high level. The nurses’ opinions on advance directives for care of terminal stage among nurses in each proficiency level showed no statistically significant difference in 7 out of 10 items but differed among proficiency level in the following items: 1) Denial of treatment for advance directive was not considered an act of suicide or hurting oneself; 2) When someone close to them such as a parent, had advance directive they were willing to comply; and 3) Following advance directive treatment helped patients to die with the dignity of human beings. In all three items, novice nurses were less likely to agree with the item. There were statistically significant differences at the 0.01 and 0.05 levels, respectively.

Conclusion: The opinion of nurses on the advance directives for care of terminal stage was at a moderate to high level. Therefore more knowledge of section 12 of the National Health Act 2550 should be provided to nurses by knowledge sharing among nurses of all proficiency level. The result should be considered for conducting nursing practice guideline of advance directives for care of terminal stage.