BackgroundMental health problems among junior doctors in Malaysia pose a significant concern, as they not only adversely affect their overall well-being but also impact the quality of health services they provide. Therefore, it is important to implement interventions aimed at preserving their mental health. This study aimed to evaluate the effectiveness of the Sanubari Optimal Health Program (OHP) intervention in enhancing the mental well-being of junior doctors in Malaysia.MethodsThe study utilised a quasi-experimental design involving 204 junior doctors who participated in the intervention. The Sanubari OHP Intervention Package was employed alongside self-administered questionnaires for mental health and well-being assessment. To evaluate the effects over time, repeated measures ANOVA was employed to analyse within-group and between-group changes in various endpoints, as measured at different assessment time points.ResultsThe study revealed that self-efficacy and adaptive coping behaviours scores increased over time among the intervention group and decreased among the control group. Yet, depression and anxiety scores decreased significantly over time among the intervention group but not in the control group. No significant differences were observed in well-being and maladaptive coping strategies among the groups.ConclusionsThis study showed promising results regarding the effectiveness of Sanubari OHP in improving mental well-being among junior doctors.