The study focuses on the sustainability of the groundwater use for domestic and agricultural purpose in Raya and Kobo valleys. The Raya valley, which comprises of Alamata, RayaAzebo, Enda-Mehoni, Ofla weredas is found in southern Tigray regional state bounded within in 12° 5'-12° 58' north latitude and 39° 20' -39° 53' east longitude. The Kobo valley, which comprises of Kobo wereda, is found in northern Wello of Amhara regional state bounded with in 11° 5'-12° 11' north latitude and 39° 22' -39° 48' east longitude. The study areas are endowed with groundwater fertile land livestock and agro-climatic conditions. The sustainability of the groundwater use for domestic and agricultural purpose is evaluated using indicators of groundwater importance (total groundwater abstraction / total renewable groundwater resource), indicators of groundwater exploitation and groundwater vulnerability indicator. To estimate the value of these indicators, the annual recharge is estimated using water balance method and chloride mass balance method. The total annual recharge estimated, for Raya valley and Kobo valley, based on the former method is 129.9MCM and 85.59MCM, respectively. Further, using the latter method it was estimated that 52.48mm/year for Raya valley and 52.8mm/year for Kobo valley. Moreover, the total groundwater abstraction is estimated by computing the crops irrigation requirement using CROPWAT 8 software and per capita demand (20l/day) of the inhabitants that live in the valley. Water table fluctuation, which is used in the computation of exploitable groundwater resource, is estimated using cumulative rainfall departure method. In conclusion, the current groundwater use (development) in the two valleys is sustainable and it is at the stage of under exploitation. In Raya valley, when the intended / proposed pressurized irrigation practice, which covers (26,100ha) using groundwater, is implemented, the groundwater development will be reached unsustainable and moderately exploitable stage. The groundwater quality of the western part of the valleys area is moderately vulnerable whereas the central and eastern parts of the valleys are vulnerable. At the end, the current groundwater use for domestic and agricultural purpose should be enhanced. But, when the intended/proposed agricultural practice reaches at maximum production in Raya valley, additional recharge must be implemented. To minimize the groundwater vulnerability, proper waste disposal site must be constructed, Continuous groundwater quality assessments must be carried out, when fertilizer(s) is/are applied for the farmland and vulnerability map of the areas should be prepared.