This cross-sectional survey research investigated mental health symptoms and quality of life among Chinese parents and their children with eczema at a paediatric dermatology clinic in Hong Kong from November 2018 to October 2020. Health-related quality of life, eczema severity, and mental health among children with eczema, as well as their parents' mental health, were studied using the Children's Dermatology Life Quality Index (CDLQI), Infants' Dermatitis Quality of Life Index (IDQOL), Nottingham Eczema Severity Score (NESS), Patient-Oriented Eczema Measure (POEM), and the Chinese version of the 21-item Depression, Anxiety, and Stress Scales (DASS-21). In total, 432 children and 380 parents were recruited. Eczema severity (NESS and POEM) and health-related quality of life (CDLQI) were significantly positively associated with parental and child depression, anxiety, and stress levels according to the DASS-21, regardless of sex (children: r=0.28- 0.72, P<0.001 to 0.007; parents: r=0.20-0.52, P<0.001 to 0.034). Maternal depression was marginally positively associated with increased anxiety in boys with eczema (r=0.311; P=0.045). Younger parents had higher risk of developing more anxiety and stress compared with the older parents (adjusted odds ratio [aOR]=-0.342, P=0.014 and aOR=-0.395, P=0.019, respectively). Depression level of parents with primary to secondary education was 58% higher than their counterparts with post-secondary education or above (aOR=-1.579; P=0.007). Depression, anxiety, and stress among children with eczema and their parents were associated with eczema severity and impaired quality of life in those children. These findings regarding impaired mental health in children with eczema and their parents highlight the need to include mental well-being and psychosocial outcomes in future studies and clinical practice.