Technical Abstract: Race TTKSK (Ug99) of Puccinia graminis f. sp. tritici is a serious threat to wheat production worldwide because of its wide virulence on many cultivars and rapid spread in eastern Africa and southwestern Asia. Emmer wheat (Triticum turgidum ssp. dicoccum) is known to be a source of resistance to stem rust, but has not been evaluated against race TTKSK. In attempts to identify and characterize stem rust resistance genes effective against race TTKSK at the seedling stage, we evaluated 359 accessions of emmer wheat with race TTKSK and other races with broad virulence. A high frequency (31.8%) of accessions were resistant to TTKSK at the seedling stage with low infection types ranging from 2= to 2+. Thirty-seven accessions exhibited a resistant to moderately resistant response in Debre Zeit, Ethiopia and St. Paul, MN nurseries in 2010 and 2011. Studies were conducted to determine the inheritance of TTKSK resistance in five accessions at the seedling stage. Results from evaluating F2 and F2:3 generations derived from resistant × susceptible crosses revealed that resistance was conferred by single genes. One additional resistance gene effective against race TTTTF was identified in all the resistant parents. Results from this study indicated that emmer wheat is a rich source of resistance to race TTKSK, and may contribute novel stem rust resistance genes. Since emmer wheat shares the same genome as durum wheat and is in cultivated form, resistance genes should be easily transferred to durum wheat by conventional breeding approaches.