Aims: This paper shows the contribution of participatory research to upgrade the integration of legumes into cropping systems. Place and Duration of Study: The investigation is based on survey data collected in 2008 and 2011 (two reference years) and 2021 and 2022 (current situation) in the village of Koumbia in western Burkina Faso. Methodology: Data was collected through surveys and field measurements. The surveys were conducted with a sample of fifty (50) volunteer farmers. In 2008, 2011 and 2022, the same questionnaire was administered to all 50 farmers. Field measurements with GPS (Global Positioning System) were conducted on crop area. Results: The results show that the proportion of area under legumes crops increased by 77,38% after 15 years. Other legumes crops (Glycine max and Mucuna sp.) were introduced in addition to those previously grown (groundnuts and cowpeas) by farmers. Surface cropped in sorghum (35.36%) and millet (82.79%) declined while cotton and maize remain the main crops in the zone. The results on farmers’ perception show that they prefer single cropping of legume crops as their insertion modality in the existing farming systems compared to their association with cereals. Conclusion: The study shows that the role of legumes is increasing in the cropping system, and represents an opportunity to succeed in the agro-ecological transition, even though the intercropping of cereal/legume, which is put forward by the theoretical models of the agro-ecological transition, is still little practiced. The structuration of the legume sector can be a condition for achieving it.