The title of the present doctoral thesis is “Efficiency and adoption of innovative rice-fish systems on the highlands of Madagascar”. It seeks to improve the agronomic, ecological, environmental and socio-economic efficiency of rice-fish cultures for their appropriation in the Highlands of Madagascar. Even though Madagascar was the pioneer country of rice-fish farming in Africa, 150 years ago, rice-fish farming in Madagascar has not developed as it should be unlike in Asia. Socio-economic surveys will determine blockages, incomes, technical routes, and the reasons for adopting and not adopting rice-fish innovations as well as their relationship with poverty and gender. Experiments in experimental controlled station and in a farmer’s site have been carried out. The innovation concerns the determination of the efficient area of fish refuge, the appropriate organic or mineral fertilization and the most efficient rice varieties as well as the socio-economic factors favorable to their appropriation.