Background: The concept of patient advocacy is still poorly understood and not clearly conceptualized. Therefore, there is a gap between the ideal of patient advocacy and the reality of practice. In order to increase nursing actions as a patient advocate, a comprehensive and clear definition of this concept is necessary. Research objective: This study aimed to offer a comprehensive and clear definition of patient advocacy. Research design: A total of 46 articles and 2 books published between 1850 and 2016 and related to the concept of patient advocacy were selected from six databases and considered for concept analysis based on Rodgers’ evolutionary approach. Ethical considerations: This study was approved by the Research Ethics Committee of Tarbiat Modares University. Findings: The attributes of patient advocacy are safeguarding (track medical errors, and protecting patients from incompetency or misconduct of co-workers and other members of healthcare team), apprising (providing information about the patient’s diagnosis, treatment, and prognosis, suggesting alternatives of healthcare, and providing information about discharge program), valuing (maintaining self-control, enabling patients to make decisions freely, maintaining individualization and humanity, maintaining patient privacy, and acting in the patients’ values, culture, beliefs, and preferences), mediating (liaison between patients, families, and healthcare professionals, being patients’ voice, and communicate patient preferences and cultural values to members of the healthcare team), and championing social justice in the provision of healthcare (confronting inappropriate policies or rules in the healthcare system, identifying and correcting inequalities in delivery of health services, and facilitating access to community health services and health resources). Discussion and conclusion: The analysis of this concept can help to develop educational or managerial theories, design instruments for evaluating the performance of nurses in patient advocacy, develop strategies for enhancing patient advocacy, and improve the safety and quality of nursing care in the community and healthcare system.