Many U.S. schools use visible security measures (security cameras, metal detectors, security personnel) in an effort to keep schools safe and promote adolescents' academic success. This study examined how different patterns of visible security utilization were associated with U.S. middle and high school students' academic performance, attendance, and postsecondary educational aspirations. The data for this study came from two large national surveys--the School Crime Supplement to the National Crime Victimization Survey (N = 38,707 students; 51% male, 77% White, M[subscript Age] = 14.72) and the School Survey on Crime & Safety (N = 10,340 schools; average student composition of 50% male, 57% White). The results provided no evidence that visible security measures had consistent beneficial effects on adolescents' academic outcomes; some security utilization patterns had modest detrimental effects on adolescents' academic outcomes, particularly the heavy surveillance patterns observed in a small subset of high schools serving predominantly low socioeconomic students. The findings of this study provide no evidence that visible security measures have any sizeable effects on academic performance, attendance, or postsecondary aspirations among U.S. middle and high school students. The following are appended: (1) Variables Used in Propensity Score Models (table); and (2) Effects of Visible Security Measures on Academic Outcomes, SCS Student Surveys (N = 38,707) (table). [At time of submission to ERIC this article was in press with "Journal of Youth and Adolescence."]