Reference evapotranspiration (ET0) is an essential parameter for hydrological modeling, irrigation planning and for studying the impacts of climate change on water resources. This work evaluate 20 alternative methods of estimating ET0 in order to adapt them to the climatic context of the 3 mains basins of Senegal where very little climate data is available. The methods of Valiantzas 1, Doorenboss & Pruitt and Penman are the most robust for the estimation of ET0 in this context.