Confirmatory factor analysis was used with a multitrait (attention-deficit/hyperactivity disorder-inattention, attention-deficit/hyperactivity disorder-hyperactivity/impulsivity, oppositional defiant disorder toward adults, academic competence, and social competence) by multisource (mothers and fathers) matrix to test the invariance and convergent/discriminant validity of the 5-factor model between mothers' and fathers' ratings of Thai adolescents (Year 1: n = 872; Year 2: n = 903; Year 3: n = 700; Year 4: n = 984) with the Child and Adolescent Disruptive Behavior Inventory (G. L. Burns, T. Taylor, & J. Rusby, 2001). The results showed equality of like-item loadings, intercepts, and residuals, as well as like-factor variances, covariances, and means between mothers' and fathers' ratings within each of the 4 yearly samples. In addition, the between-parent factor correlations showed convergent and discriminant validity with the within-parent factor correlations, showing discriminant validity for each year as well. These results for Thai adolescents and similar results (G. L. Burns et al., 2008) for mothers' and fathers' ratings of Brazilian, Thai, and American children provide broader support for the construct validity of the scale. The confirmatory factor analysis invariance and convergent/discriminant validity procedure with multiple sources is considered to provide a much more sophisticated procedure to evaluate the construct validity of attention-deficit/hyperactivity disorder and oppositional defiant disorder rating scales than a single-source approach. (Contains 1 footnote, 2 tables, and 1 figure.)