Abstract Background When Public Health is challenged by issues related to migrant and vulnerable populations, health facilitators’ profiles are crucial to accessing communities and increasing intervention effectiveness and acceptability. The French overseas region, French Guiana, is concerned with a migrant population living in vulnerable conditions far from healthcare and being a major reservoir of malaria. Curema is an intervention implemented to fight malaria in this population by distributing RDTs, and treatments after an appropriate training of participants. Facilitators from the community are employed to provide health education and enroll participants. Objectives An intensive theoretical-practical training program was realized to enable facilitators to master procedures related to the intervention. The training was designed using the CDC Training-of-Trainers (ToT) framework and adult learning principles. It was composed of initial and on-the-field training, both based on bidirectional, participative, and dynamic working spaces. A mixed-method evaluation was carried out to assess training effectiveness and quality. Results Group dynamics and adaptations driven by facilitators’ needs were key elements of a high-quality training program. Satisfaction was elevated for training format and learning results. Statistically significant improvements in knowledge level demonstrated good effectiveness. During the initial training, difficulties persisted regarding some tasks to be performed during the intervention: further on-the-job training addressed them, improving facilitators’ practices in the field. Conclusions High-quality, effective, and appropriate training programs are required for intervention involving facilitators’ profiles. Training design is crucial to achieve it. ToT model has been shown to allow high satisfaction, learning results, and good implementation in the field. Initial and on-the-job training are an indispensable continuum to sustain good practices and motivation. Key messages • If health facilitators from the community are actors in public health interventions, appropriate training is necessary to ensure good implementation. • ToT seems an optimal model for training health facilitators.