The current study proposes a flexible approach to studying informant discrepancies: Latent Difference Scores modeling (LDS). The LDS approach is demonstrated using an empirical example in which associations between mother–adolescent and father–adolescent discrepant parenting perceptions, and concurrent and later adolescent externalizing behaviors, were investigated. Early adolescents (N = 477, aged 12–15 years), mothers (N = 470), and fathers (N = 440) filled out questionnaires about mothers’ and fathers’ parenting. Results using the LDS approach are compared to results obtained by the 2 existing approaches for informant discrepancies: Observed Difference Scores modeling (ODS) and Polynomial Regression Analyses (PRA). Results from the LDS approach show that adolescents perceive their mothers’ and fathers’ parenting less favorably than mothers and fathers themselves, and that stronger mother–adolescent discrepancies are consistently related to stronger father–adolescent discrepancies. Parent–adolescent discrepancies were concurrently associated with more aggressive and rule-breaking behaviors, but not longitudinally. Results generalized across the 2 discrepancy approaches, but only very few significant associations were found in the PRA. Advantages and limitations of all 3 approaches to studying informant discrepancies are discussed.