Background <p>Studies comprehensively testing the temporal ordering of early cumulative stress exposure, parenting, and trajectories of behavioral problems during adolescence while accounting for confounds remain understudied.</p> Objective <p>Guided by the Family Stress Model, the study examines maternal knowledge of teen’s activities, affiliations, and whereabouts as mediating association between early cumulative parent-based stressors and growth rates in aggression and delinquency across early adolescence.</p> Method <p>Using nationally representative data of mothers and their children (<i>N</i> = 1364) from the NICHD Study, construct of cumulative stress was assessed when study child was between 1-month to 9 years. Maternal knowledge was measured at age 11 and aggression and delinquency were assessed at ages 11, 12, and 15 using maternal reports.</p> Results <p>A parallel latent growth curve modeling showed a decreased rate of growth in aggression and an increased growth rate for delinquency over time, with substantial individual variations. Direct associations revealed that higher cumulative stress exposure predicted a slower rate of decline in aggression and a faster increase in the growth rate of delinquency. Moreover, higher cumulative stress predicted lower maternal knowledge, which predicted lower starting levels of delinquency, but faster increases in delinquency over time. Mediation tests showed that higher cumulative stress was indirectly linked to delinquency intercept via lower parental knowledge.</p> Conclusion <p>Findings underscore the carryover impact of early cumulative parent-related stressors on subsequent gains in adolescent’s behavior problems, and limited parental knowledge efforts is one mechanism accounting for the association, particularly highlighting the variable influences of parental knowledge on behavior problems during adolescence.</p>