The COVID-19 emergency has fostered an increasing risk of experiencing distress and negative emotions in parents that turned into heightened stress for children. In this study, we aim to evaluate the effects of parental stress, children's resilience, and previous adversities on the development of internalizing and externalizing symptoms in children. A series of questionnaires were completed by 158 Italian parents (148 mothers, 10 fathers, mean age = 41 years) concerning them and their school-aged children (N = 158, 76 boys, mean age = 7.4 years) at two critical time points (June 2020 and December 2020). Regression analyses showed that internalizing problems were predicted only by concurrent children's resilience, whereas externalizing problems were predicted by concurrent parental flooding, children's resilience, and early parental satisfaction. Therefore, internalizing and externalizing symptoms trajectories follow different routes and are predicted by both common and distinct factors. Supporting positive parenting attitudes and behavior should be recommended to prevent the worsening of children's externalizing behaviors. At the same time, nurturing resilience in pediatric systems might be useful in preventing or reducing children's internalizing symptoms.