Parental stress is a known risk factor for coercive parenting and for lower coparenting quality. In the present study, we examined whether and how changes in parental stress of mothers and fathers from the pre-COVID-19 period (T1) into the height of the first lockdown in the Netherlands (T2) were linked to changes in coercive parenting of mothers and fathers and to changes in coparenting quality. A total of 96 families (46.9% lower or medium and 53.1% higher educational background), with mother, father, and child (53.1% girls; T1: M age = 3.44 years, SD = 0.32; T2: M age = 4.72 years, SD = 0.61) participated. To examine interrelations between parental stress (reported using the Parental Stress Scale), coparenting, and coercive parenting (both reported using the Parenting And Family Adjustment Scales), a multivariate Latent Change Score (LCS) model was employed. Higher initial levels of parental stress were associated with higher initial levels of coercive parenting and lower initial levels of coparenting quality. Similarly, stronger increases in parental stress were associated with stronger increases in coercive parenting and with stronger decreases in coparenting quality. Directions of associations and effect sizes were similar for mothers and fathers in all analyses. The results from the present study indicate the importance of a family systems perspective in prevention and intervention programs. Promotion of systematic family-based preventive and intervention activities by the government might support families during challenging times, as during the novel COVID-19 pandemic. (PsycInfo Database Record (c) 2021 APA, all rights reserved).