This article explores secondary preservice teachers' attitudes toward the use of teacher self-disclosure as a tool for citizenship education. Based on the notion that teacher self-disclosure may function as citizenship curriculum, this study addressed critical issues of teachers' sharing their knowledge about religions (including their own) and political perspectives (including their own) for citizenship education, and it explored the challenges of integrating teacher self-disclosure into teaching. Data from interviews with six preservice teachers indicate that they did not consider it acceptable for teachers to talk about their religious beliefs and political perspectives for fear of (1) disagreeing with their students, (2) the possibility of students' having limited understanding or misunderstanding, and (3) the risk of inciting conflicts with parents and the school administration. The study suggested that teacher education programs should provide courses and field experiences for preservice teachers to develop their attitudes to better comprehend citizenship curriculum and citizenship education.