Field experiments were carried out at the experimental farm of the Water Studies and Research Complex (WSRC), Station, National Water Research Center, Toshka – Abu simbel City, Egypt during the two growing seasons of 2011 and 2012 to assess the effect of water stress [25% , 50% and 75% of available soil moisture depletion] on water consumptive use (ETa) of sesame (Giza - 32 ,variety) as well as yield and yield component under sprinkler irrigation system. Reference evapotranspiration (ET_o) was estimated by some ET formulas to compare them with the actual evapotranspiration (ETa). The crop coefficient (Kc), plant characteristics and the water application efficiency (WAE) were measured.