Graduate teaching assistants (GTAs) are a pervasive presence in undergraduate education. Although GTAs are expected to successfully communicate course content to undergraduate students, they often are inexperienced and receive little training in pedagogy. Therefore, GTAs must learn effective communication behaviors in the classroom. This study furthers research on one prevalent, yet insufficiently investigated, GTA behavior: self-disclosure. Specifically, the study examines why GTAs choose to share private information with their students. Twenty-three in-depth interviews were conducted to gain an understanding of GTAs' motivations for self-disclosure. The data revealed that GTAs self-disclose to their students for six reasons: building interpersonal relationships, enhancing credibility, creating an environment of reciprocity, illustrating course material, keeping students' attention, and improving student course evaluations.