We examined correlates and predictive associations of tattoos and body piercings among 1,462 Colorado students in grades 9 to 12. More boys (19%) than girls (17%) reported tattoos, but more girls (42%) than boys (16%) reported piercings (earlobes not included). Older students reported more body modification. Structural equation models showed that although girls generally reported less deviant behavior, the indirect effect of female gender mediated through piercings was toward greater deviance that was not an artifact of girls having more piercings. Pierced girls were less school oriented than girls without piercings; they reported more substance use than boys without piercings, and pierced girls did not differ from boys in weapons possession and delinquency. However, among pierced respondents, boys still reported a greater number of deviant behaviors than girls. Educators and other adults should become aware of the possible at-risk status of body-modified adolescents, especially among girls who have piercings. (Contains 1 figure and 2 tables.)