The aim of the present study was to examine the normative developmental trajectories of toddlers' externalizing behaviors and several maternal and paternal parenting dimensions. Latent growth models were used to determine intraindividual changes and interindividual differences in these changes. One hundred and eight boys were followed from 17 months of age to 35 months of age. A significant linear decrease in attention problems and a significant linear increase in aggressive behaviors were found. Additionally, multivariate models were tested that related the developmental trajectories of externalizing behaviors to the trajectories of the parenting dimensions. The results showed meaningful contemporary relations and relations between over-time trajectories of parenting dimensions and children's externalizing behaviors.