The aim of the present study was to compare acute effects of a climbing intervention (CI) on affective responses with a different exercise intervention (swimming, SI) and an occupational therapy intervention (OTI) in children and adolescents during in-patient treatment for mental health disorders. The following study was designed as a cross-over study. Participants completed three single 60 min interventions of CI, SI and OTI. Affective responses were assessed pre and post intervention and at 20 and 40 min during intervention. The sample consisted of 33 children and adolescents in mental-health inpatient care (ᴓage: 13.3 ± 2.2 years, ♀=39.4%). A significant time effect was seen in all interventions in increasing positive and reducing negative affect, p0.144. Repeated measures ANOVAs revealed a significant time by intervention effect for affective valence (p=.011, eta²=0.09), but not for perceived activation, favouring CI over SI and OCT between pre-test and the first 20 or 40 min, respectively. All interventions showed similar effects on affective responses pre to post interventions. CI seems to increase affective valence more strongly during intervention compared to SI and OTI. The present results may have implications for therapy adherence and acute emotion regulation in children and adolescent in-patients with mental health disorders.Copyright © 2020 Elsevier B.V. All rights reserved.