This study aims to examine the effectiveness of an intervention program based on the PROSPER, a comprehensive framework which emphasises the importance of positivity, relationships, outcome, strength, purpose, engagement, and resilience in pre-service teachers’ well-being in Hong Kong. Participants were pre-service pre-school teachers (N = 77) who participated in a 1-month randomised control trial with four intervention workshops. They were randomly assigned to either intervention (n = 40) or wait-list control conditions (n = 37). A survey with measures that assessed PROSPER well-being components was administered to participants before and after the intervention. Findings of repeated measures MANCOVA revealed no significant time x group interaction effect, Wilks’ Lambda F(7, 50) = 1.66, p = .14, η² = .19. Results of univariate analyses showed that a significant time x group interaction effect existed in relationship component (η² = .08), indicating that the intervention was effective in facilitating pre-service pre-school teachers’ positive relationships with their peers. Findings underscore the potential benefits of designing positive psychological interventions for teachers amid the COVID-19 pandemic. Copyright © 2023 Informa UK Limited, trading as Taylor & Francis Group.