The purpose of this study was to examine the effects of program interventions in a school-based teen pregnancy program on hypothesized constructs underlying teens' attitudes toward sexuality. An important task related to this purpose was the validation of the constructs and their stability from pre- to postintervention measures. Data from 1,136 middle grade students were obtained from an earlier evaluation of an abstinence-based teen pregnancy prevention program (S. Weed, I. Ericksen, G. Grant, & A. Lewis, 2002). Latent trait structural equation modeling was used to evaluate the impact of the intervention program on changes in constructs of teens' attitudes toward sexuality. Gender was also taken into consideration. This investigation provides credible evidence that both 1st- and 2nd-order constructs related to measures of teens' attitudes toward risky sexual behavior are sufficiently stable and sensitive to detect program effects.