Objective: To analyze the concept of social identity of transgender persons and develop nursing diagnoses related to it. Methods: A concept analysis according to the Walker and Avant model. A scope review was carried out with a search of eight databases, a portal and two information systems, during June and July 2019. Articles, theses, and dissertations were analyzed in Portuguese, English, and Spanish, with no time frame definition. Results: Of the 6.847 productions, 10 were included, and the concept of social identity was described in 4 of them. Critical, prior, and consequential attributes for the social identity of transgender persons were identified, and the analysis of the concept substantiated the proposal of the diagnosis: Willingness to improve the social identity of the transgender person. Conclusion: Social identity establishes a relationship with health, and the proposed nursing diagnosis strengthens the sense of belonging of transgender people, enhancing their rights as citizens.