The aim of the present study was to examine perfectionism among adolescents in relation to psychiatric disorders and contact with child and adolescent mental health care services (CAMHS). The sample consisted of adolescents (16–19 years) who participated in the youth@hordaland survey and consented to a linkage to the patient registry data (n = 9072, 53.2% girls). Those who had received help from CAMHS (n = 933, 10.3%) were categorized as the clinical group, while the remaining adolescents (n = 8139, 89.7%) defined a reference group. Perfectionism was measured by the Eating Disorder Inventory-2 as a sum score (EDI-P) and subscales for Self-Oriented (SOP) and Socially-Oriented (SPP) perfectionism. The clinical group scored higher on SPP than the reference group (1.99, SD = 1.75, vs. 1.88, SD = 1.56, p < .05), but not on EDI-P or SOP. There were more high scorers in the clinical group than the reference group for EDI-P (11.8% vs. 8.9%, p < .01) and SPP (11.9% vs. 6.7%, p < .001), but not for SOP. Adolescents with depression and eating disorders scored higher on all dimensions of perfectionism compared to the reference group, also when adjusting for sex. Perfectionism was higher in the clinical group than the reference group, and this was more pronounced for SPP than SOP. Only depression and eating disorders were associated with elevated perfectionism scores in the clinical group. Perfectionism should be targeted in future longitudinal studies as well as in clinical interventions in other to strengthen the mental health among adolescents.