Viewing teacher vulnerability as a pedagogical tool, this comparative case study examined two secondary literacy teachers' use of vulnerability in relation to various instructional goals. Through the analysis of eight video-recorded lessons, we found that teachers demonstrated vulnerability through multiple ways within their literacy instruction through modeling ways of connecting personal experiences to texts, and establishing classroom norms that welcome difficult emotions and experiences. However, we also found that teacher vulnerability can sometimes lead to uncertainty, and even constrain student participation. We argue that teacher vulnerability helps establish a "humanizing pedagogy," and offer possible strategies for teachers who are vulnerable within literacy instruction. We conclude with a discussion of different levels of appropriating vulnerability as a pedagogical tool.