A latent class growth analysis (LCGA) of self-reported involvement in delinquency was performed on a sample of 1,414 boys and girls from the 1997 version of the National Longitudinal Survey of Youth. The LCGA results revealed the presence of three trajectories (high, medium, and low elevation). The three-trajectory and three-class posterior probabilities models were subsequently compared to a simple dimensional model composed of the sum of all delinquent acts reported in a 7-year period. Analyses revealed that the simple dimensional model correlated significantly better with measures of delinquency initiation and severity than the three-trajectory and posterior probabilities models. The fact that a categorical model created from the results of an LCGA analysis and posterior probabilities of class membership experienced significantly weaker effect sizes than a simple dimensional model suggests the absence of a nonarbitrary division between the trajectory groups identified in this study.