Adolescent health behaviors tend to cluster and vary by such factors as grade, age, and racial/ethnic background. A population-based instrument was needed to assess health behaviors of the students in a vocational high school in the City of Chicago. To reduce respondent burden, Child Health and Illness Profile--Adolescent Edition (CHIP-AE) was modified by omitting seven subdomains. Ninety-three boys and 245 girls voluntarily participated in the study. Pearson correlation coefficients, MANOVA, and ANOVA were used in data analysis. Modified CHIP-AE was found to have acceptable reliability and detect the expected differences of adolescent health behaviors by gender and age. Modified CHIP-AE can be used to assess adolescent health behaviors in an urban vocational high school. It can also be used to target the subgroups of students with specific needs for health services.