Recent discourse on public school reform has focused on mandatory uniform policies. Proponents of such reform measures emphasize the benefits of student uniforms on specific behavioral and academic outcomes. This research empirically tests the claims made by uniform advocates using 10th grade data from The National Educational Longitudinal Study of 1988. Our findings indicate that student uniforms have no direct effect on substance use, behavioral problems or attendance. A negative effect of uniforms on student academic achievement was found. These findings are contrary to current discourse on student uniforms. We conclude that uniform policies may indirectly affect school environment and student outcomes by providing a visible and public symbol of commitment to school improvement and reform.