Parenting during the COVID-19 pandemic is highly challenging, with parents having to meet various demands simultaneously. An increase in adverse childhood experiences (ACEs) has been widely predicted, but empirical evidence is still scarce. This study aimed to (1) generate representative data on pandemic-related stress, parental stress, general stress, parental subjective and mental health, and the occurrence of ACEs; (2) identify risk factors for an increase in ACEs, and (3) provide qualitative data on parents’ experiences. A representative survey was conducted in Germany in August 2020 with 1024 parents of underage children (Mage = 41.70, 50.9% female). More than 50% of parents reported being stressed by social distancing and the closure of schools and childcare facilities. Parental stress increased significantly during the pandemic (d = 0.21). Subgroups of parents also reported very high levels of depressive symptoms (12.3%) and anxiety (9.7%). Up to one-third of the sample reported ACEs in the child’s lifetime. In this group, 29.1% reported an increase in children witnessing domestic violence during the pandemic, and 42.2% an increase verbal emotional abuse. These families were characterized by higher parental stress, job losses, and younger parent and child age. Positive aspects of the pandemic related primarily to personal or family life (e.g. slower pace of life, increase in family time). While some parents coped well, a particularly negative pattern was observed in a subgroup of families that experienced an increase in ACEs. Parental stress emerged as important target point for interventions addressing the negative sequelae of the pandemic.