This article presents the results of a study on the project 'Teacher Educators Study Their Own Practices'. Nine teacher educators participated and conducted a self-study into their own practices. The leading question of this article is whether their self-studies contributed to the development of their professional identities. Data sources were digital logbooks, exit interviews, and follow-up questionnaires. The results show that conducting self-study research supports theoretical growth, ongoing development, the production of knowledge, and the enhancement of self-confidence. What these results could mean for the teacher educators themselves and their practices, and for the professional community of teacher educators, is discussed in the final section of this article.