There are few studies on psychosocial problems in adolescents with eczema. We performed a cross-sectional, questionnaire-based study to explore the relationship of suicidal ideation, mental health problems, and social functioning with eczema. A total of 4,744 adolescents (18-19 years) were invited for the study, of whom 3,775 (80%) participated. The overall prevalence of current eczema was 9.7%. Among those with current eczema, 15.5% reported suicidal ideation compared with 9.1% among those without eczema, significantly associated in a multivariate model (odds ratio 1.87, 95% confidence interval 1.31-2.68). In a subgroup analyses, the prevalence of suicidal ideation in those with both eczema and itch was 23.8%, and was significantly associated, compared with those without eczema (3.57, 2.46-5.67). Eczema was associated with mental health problems assessed by the Strength and Difficulties Questionnaire (1.72, 1.21-2.45) and the Hopkins Symptom Checklist 10 (1.63, 1.23-2.16). Five questions assessed social function: feeling attached to family and friends; thriving at school; experiencing bullying; and romantic relationships. Boys with current eczema were less likely to have had romantic relationships (1.93, 1.21-3.08). Eczema in late adolescence is associated with suicidal ideation and mental health problems but rarely with social problems. Our findings point to the importance of addressing mental health issues in adolescents with eczema.