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. (Contains 2 tables.)