This study investigated the inter-rater reliability when 169 out of 171 clinicians working in 10 Norwegian child and adolescent mental health services rated 20 written vignettes using the following outcome measures: Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA), Children's Global Assessment Scale (CGAS) and Global Assessment of Psychosocial Disability (GAPD). Three clinicians rated both patients and vignettes. On vignettes the intraclass correlation coefficient (ICC) for the HoNOSCA total score was 0.81 (single scales 0.47-0.96), for the CGAS 0.61 and for the GAPD 0.60. The reliability was not lower on patients. The rater's profession, experience or clinic did not have effect on the scores.