To succeed with participatory occupational health and safety (OHS) interventions it is not sufficient to consider only the employees’ perspective, as perceptual distance between leaders and teams is known to have an effect on outcomes. The aim of this paper is to investigate the impact of leaders’ and teams’ perceptions of a non-threatening interpersonal atmosphere of trust and support (i.e., a participative safety climate) on employees’ changes in confidence in their ability at work to 1) interact socially (social self-efficacy), 2) manage emotions (emotional self-efficacy), and 3) solve tasks (cognitive self-efficacy) following a participatory OHS intervention. Thirty leaders and 348 employees in 28 teams from 5 organizations completed surveys before and after the intervention. Polynomial regression with response surface analyses revealed that agreement between leaders and teams regarding participative safety before the intervention related positively to all three self-efficacy dimensions after the intervention. These results exemplify how leaders’ and their teams’ different perceptions of the climate before implementing an intervention may affect changes in intervention-relevant outcomes. The findings contribute to the emergent understanding of how interventions are dependent on the organizational context where they are implemented. It also points to the need to consider non-linear relations in intervention research. The findings suggest that in practice, organizations conducting participatory OHS interventions should assess and address pre-intervention climate factors to succeed. Congruence matters.