The main purpose of the study is to examine the relations between a mandatory school uniform policy and student problem behavior. The study is based on the School Survey on Crime and Safety (SSOCS) 2003-04 data. Analyzing data from 421 urban schools, the study found that schools adopting a mandatory uniform policy are negatively associated with rates of student problem behaviors except at the high school level. As with other school safety initiatives, parental involvement at the elementary school level, and teacher training and community efforts at the high school level were revealed as negative predictors of student problem behavior.