The aims of this study were to introduce the Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) into the clinical practice, to assess the possibilities to use HoNOSCA in the interdisciplinary teamwork of child psychiatric inpatient unit and to analyse differences in evaluation of HoNOSCA among team members scoring different diagnostic groups of children. HoNOSCA was translated into Lithuanian and team members were trained to use the scale. Inter-rater reliabilities between various pairs of specialists and between all members of the team were calculated using intraclass correlations calculated for each item of the scale and total score. Scoring differences in children with externalized and internalized disorders between psychiatrists–psychologists versus nurses–caretakers were analysed using t-test. The analysis showed that intraclass correlations estimates of reliability of the HoNOSCA discharge scores were highest for ratings by child psychiatrists–psychologists and nurses–caretakers. Analysis of ratings of patients with externalized and internalized disorders types showed differences in scoring disruptive/aggressive behaviours, self-care and family relationship scales. HoNOSCA had satisfactory inter-rater reliability in clinical multidisciplinary practice of child psychiatric inpatient unit. Implementing HoNOSCA in routine clinical practice and analysis of the rating differences among the multidisciplinary team members was useful to highlight possibilities for improvement of quality of services provided and building more constructive teamwork.