Studies show a high level of mental health problems among refugee children and adults. This study aimed to examine psychiatric disorders among refugee children in early adulthood. A total of 15,264 young adult refugees, who obtained residence permission January 1, 1993 to December 31, 2010, were matched 1:6 on age and sex with 99,313 Danish-born children. Rate ratios (RR) of having a first-time in- or outpatient hospital diagnosis with an affective (F30–39), psychotic (F29–30), neurotic (F40–48), or any psychiatric disorder (F00–99) according to ICD-10 were computed. Refugees had higher RRs of psychotic (RR: 1.81, 95%CI: 1.41–2.32) and nervous (RR: 1.28, 95% CI: 1.14–1.43) disorders compared with Danish-born children. The RRs of having an affective disorder among refugees was 0.74 (95% CI: 0.60–0.90) compared with Danish-born children. Sex, geographical origin, migrant status, household income, age at residence permission, and accompanied/unaccompanied arrival predicted psychiatric contacts among refugees. A focus on both prevention and treatment in vulnerable groups is needed.