Background: Pain management is a fundamental human right for everyone who experiences it. The management of pain is an ethical obligation for all health professionals. Professional values have an important place in appropriate clinical decision-making. Research aim: This study was conducted to determine the relationship between nurses' ethical attitudes in pain management and their compliance with professional values. Research design: The study was conducted as a descriptive and correlational research. The study data were collected by online survey method using the Introductory Characteristics Form, Ethical Attitude Scale for Pain Management in Nursing, and Nurses Professional Values Scale – Revised. Participants and research context: The population of the study consisted of nurses working in tertiary treatment centers in a country. A total of 388 nurses participated in the study. Ethical considerations: Ethical approval was obtained from the University Ethics Committee. Consent was obtained from the nurses. Results: The mean total score of the Ethical Attitude Scale for Pain Management in Nursing was 98.96 ± 9.37, and the mean total score of the Nurses Professional Values Scale was 101.51 ± 15.20. The scores of the Ethical Attitude Scale for Pain Management in Nursing were positively and moderately correlated with the total scores of the Professional Values Scale. Compliance with professional values explained 41% of the total variance of ethical attitude for pain management. Conclusions: In this study, it was found that nurses' ethical attitudes for pain management and compliance with professional values were at a high level, compliance with professional values was associated with ethical attitudes for pain management, and ethical attitudes for pain management decreased with increasing working years. A nurse with high ethical sensitivity and compliance with professional values can easily recognize ethical problems, effectively manage the ethical decision-making process, and provide appropriate patient care.