Lake Tana Basin which is found in Northwest highlands of Ethiopia has high potential forrnirrigation agriculture, hydroelectric power development and ecotourism. This basin has beenrnidentified as one of the economic growth corridors of the country and several hydropowerrnand irrigation projects are being implemented. Hence, there is an increasing demand of waterrnutilization and the water resource systems show variations in their accumulated flow,rndistribution and overall storage volume with time. The basic objective of this research was tornestimate the daily and seasonal evapotranspiration of Tana basin and mapping its spatialrndistribution in different land use and land cover types. The Surface Energy BalancernAlgorithm for Land (SEBAL Model) was applied to three Landsat TM satellite imagesrncorresponding to November 18 and 27, 2011 to produce estimates of instantaneous actualrnevapotranspiration at 30Ã—30m resolution for the satellite over pass time. Then, therninstantaneous actual evapotranspiration was extrapolated to the daily ET value and seasonalrnaccumulated ET values using the evaporative fraction which derived from the satellite imagesrnand the Penman Monteith reference evapotranspiration that was computed fromrnmeteorological data of the basin. The daily Penman-Monteith reference evapotranspirationrnET0 which calculated from meteorological data of the basin was found as 4.3 mm/day. Thernactual evapotranspiration of the basin computed using SEBAL model ranges from 0 to 4.3rnmm/day that observed on bare lands and water bodies of the basin, respectively. The largernportion of the basin has the range of evapotranspiration between 1.3 to 2.3 mm/day whichrncovered by agricultural crops and grasslands. The dry season evapotranspiration of the basinrnalso measured between 20 to 439 mm depth of water. The spatial distribution ofrnevapotranspiration is related to the distribution of vegetation in the basin. The eastern andrnwestern parts of the basin show lower evapotranspiration corresponding to their little or nornvegetation cover while the downstream of the Lake has relatively higher evapotranspirationrndue to its relatively dense vegetation cover. Finally, the daily SEBAL ET was compared tornthe Penman Monteith daily reference ET and the linear regression analysis shows that dailyrnET of the SEBAL model has a strong relationship with Penman-Monteith referencernevapotranspiration of the study area.rnKey Words: Evapotranspiration, Remote Sensing, Surface Energy Balance, SEBAL Model