Background <p>The COVID-19 pandemic significantly impacted the mental health of children and adolescents, particularly those from low-income families and adolescent girls. The long-term effects remain unclear. This study assessed the mental health measured by emotional and behavioural problems and quality of life (QoL) among German children and adolescents, emphasising socio-economic status and gender differences. The help-seeking behaviour among families of children with mental health problems was also examined.</p> Methods <p>A nationwide representative online survey was conducted in April/May 2024. <i>N</i> = 1,530 children and adolescents (ages 8–17) and their parents participated. The self- and parent-report survey assessed behavioural and emotional problems (Strength and Difficulties Questionnaire). QoL (KIDSCREEN-10 Index) was rated in self-report. Parents reported on past help-seeking behaviour within and outside of school via items constructed for the present study.</p> Results <p>Behavioural and emotional problems (21.1% in self-report, 22.4% in parental report) and low QoL (27.3%) were higher than pre-pandemic levels. Children from low-income families were particularly affected. Of all parents, 23.7% reported a need for help due to their child’s mental health issues in the last 12 months, with 28.4% of these parents not seeking professional support. Among those who sought help, most contacted multiple services, with teachers, psychotherapists and general practitioners being the most frequently contacted services. Families who secured a therapy placement waited an average of 12 weeks for an initial appointment and 18 weeks to begin therapy.</p> Conclusions <p>Behavioural and emotional problems as well as low QoL seem to stabilise at a rate higher than the pre-pandemic baseline, indicating a need for ongoing monitoring, adjustment to the mental health system and further research on correlates and causes of this stabilisation.</p>