Background <p>Mental health—defined as a state of well-being enabling people to realise their potential, cope with daily stress, perform productive work, and contribute positively to their communities—is still perceived by the majority of people in low-income countries, including primary school teachers, as mental ill-health. This study aimed to understand the perceptions and explanatory factors of primary school teachers’ commitment to promoting mental health in schools in the urban Democratic Republic of Congo (DRC).</p> Method <p>This qualitative study was conducted in the urban DRC, especially in the city of Kinshasa. We collected data by conducting face-to-face, in-depth individual interviews with 24 primary school teachers from 12 schools (private, public and faith-based). We analysed the data according to Braun and Clarke’s reflexive thematic analysis approach. The results were organised around the following themes: teachers’ understanding of mental health, factors explaining teachers’ commitment to promoting mental health in schools, perceived obstacles, current practices, and mental health needs and expectations.</p> Results <p>Participants perceived mental health in school as a concept associated with “madness” or simply misinterpreted it. They stated that they perform mental health promotion activities based on their knowledge, including identifying pupils with mental health conditions, providing psychological first aid, and referring them to specialist services. Their commitment to promoting mental health in schools depended on their personal motivations and perceived institutional support. However, several factors, such as lack of training, lack of resources, and lack of sustained institutional support, were cited as perceived obstacles to their commitment. Participants highlighted the need for specific training in mental health promotion and advocated for integrating mental health into school curricula to strengthen its promotion.</p> Conclusion <p>The findings reveal that primary school teachers in Kinshasa still perceive mental health more as the presence of mental disorders than as positive mental health. Mental health promotion is not being implemented optimally in primary schools, as several perceived obstacles affect teachers’ commitment. These findings point to the need to revitalise mental health promotion in primary schools, particularly by establishing psychological support structures in schools and training teachers in mental health promotion.</p>