Despite the sizeable portion of foreign language (FL) instruction provided by graduate students now as teaching assistants (TAs) and in the future as faculty, few studies have considered TAs' perspectives on their own professional development. To inform the professional development of FL graduate students as teachers, the present study updated and expanded on Brandl (2000) and Gonglewski and Penningroth (1998), who surveyed FL TAs about their perceptions of professional development opportunities. Using both quantitative and qualitative data from a nationwide online questionnaire completed by TAs (N = 94) and follow-up Skype interviews (N = 9), the present study gave a voice to TAs by asking them which professional development opportunities they valued and what constraints limited their participation. TAs exhibited an apparent lack of awareness about the possible responsibilities of their future careers and the evaluation criteria used in academia, resulting in a disconnect between the professional development opportunities in which they participated and those that would actually prepare them for the long term. In light of TAs' perceptions and practices, recommendations are provided to enhance future TA professional development.