This study examines whether bullies' gender conformity, pressure to conform to gender norms (felt pressure), and experiences of homophobic name-calling are associated with a tendency to bully gender conforming victims (GCV) and gender non-conforming victims (GNCV). Longitudinal changes were analyzed on all peer interactions in an entire 6th-grade cohort over two-time points during the academic year (152 girls and 128 boys). Experiencing homophobic name-calling at Time 1 predicted perpetrating bullying against GNCV at Time 2. Only for boys, one's own gender conformity predicted bullying GNCV at Time 2. No significant associations with bullying GCV at Time 2 were found. Bullying GNCV may represent a defensive reaction to demonstrate bullies' own gender conformity. Particularly among male bullies, one's own gender conformity can affect the selection of victims based on their gender conformity. This study has important implications for the development of interventions to reduce aggressive behaviors against GNCV in middle school.