Lesbian, gay, bisexual, and transgender (LGBT) youth may face particularly hostile school climates, as they often report experiencing harassment, discrimination, and other negative experiences in school. LGBT youth, regardless of their gender identity, often face victimization and stigmatization based on both sexual orientation and gender expression. The authors examine transgender students' experiences with regard to indicators of negative school climate, such as biased language, experiences of harassment and assault, and the impact of victimization on educational outcomes. The authors also investigate transgender students' engagement in their school community and access to institutional resources. Data used in this report come from the Gay, Lesbian and Straight Education Network's (GLSEN) fifth National School Climate Survey, which was conducted during the 2006-2007 school year. Two methods were used in order to locate participants in an effort to obtain a representative sample of LGBT youth: outreach through community-based groups serving LGBT youth and outreach via the Internet, including targeted advertising on the social networking site MySpace. This report examines the specific experiences of the 295 students in the survey who identified as transgender. These transgender students were between 13 and 20 years of age, and the majority of the sample was White, and identified as gay or lesbian. Findings demonstrate that transgender students frequently face extremely hostile school environments. Similar to non-transgender lesbian, gay, and bisexual students, most transgender students hear biased language, feel unsafe in school, are regularly harassed, and lack LGBT-related resources and supports. Compared to their non-transgender peers, transgender students consistently reported higher levels of harassment and assault, were less likely to feel like a part of their school community, and had poorer educational outcomes. Transgender students were also more likely to be involved with LGBT-related issues in their schools, perhaps because they are faced with unique challenges in school, such as accessing gender-segregated facilities and being addressed by their preferred names and pronouns. Educators, policymakers, and safe school advocates must continue to seek to understand the specific experiences of transgender students, and implement measures to ensure that schools are safe and inclusive environments for all LGBT youth. (Contains 50 notes, 32 figures, and 4 tables.)