Background The COVID-19 pandemic impacted the economies, social relationships, and mental health of the population globally. A growing number of research presents empirical evidence for the...Show moreBackground The COVID-19 pandemic impacted the economies, social relationships, and mental health of the population globally. A growing number of research presents empirical evidence for the negative psychological consequences of the lockdowns, such as increased anxiety and stress. However, the long-term mental effects, especially on children and their parents, are unclear and need to be further investigated. Aims This paper aims to examine whether there is a difference in the levels of anxious and shy behaviour in five-year-old children and in parental stress in their parents due to the pandemic. Method The data was collected as part of the "Jij en Je Gezondheid" project, executed by the Gemeentelijke Gezondheidsdiensten region. Inclusion criteria included children around the age of five and their parents who live in Amsterdam. Independent samples t-test was run to investigate whether there is a difference in anxious and shy behaviour in the children and parental stress before and after the COVID lockdowns. Results Levels of anxious and shy behaviour were higher after the COVID lockdowns in children as compared to the before lockdowns group. Parental stress was reported to also increase after the COVID lockdowns. Conclusions The study emphasizes the negative effect of the COVID-19 pandemic on children’s anxious and shy behaviour and their parents' stress levels. The findings highlight the need for tailored interventions for families to decrease the long-term psychological burden of the pandemic, as well as additional research to fully understand the problem.Show less