This study evaluated a brief social self-efficacy (SSE) measure among 4,122 public middle school adolescents and its association with aggressive behavior. Data analytic procedures included calculating mean ratings, standard deviations in addition to inspecting the scale's reliability, internal structure, and relationships to demographic and aggressive behavior (physical fighting, being bullied, and avoiding school) variables. Results revealed acceptable evidence of internal consistency reliability, internal structure, and relationships to the demographic and aggressive behavior variables. Females reported significantly higher SSE than males, seventh grade students reported significantly higher SSE than eighth grade students, while White and Black students reported significantly higher SSE than Asian students. Significantly lower SSE ratings were also noted for those who reported aggressive behavior. Results suggest SSE may be an important component in the adolescent developmental process and this brief measure of social self-efficacy may further facilitate inclusion in more comprehensive assessments for early adolescents.