Carstens V, one of the wheat cultivars used to differentiate races of Puccinia striiformis (stripe rust or yellow rust) in Europe, was crossed with stripe rust susceptible cultivars and cultivars with genes for resistance to the disease to determine the genetic basis of its stripe rust resistance. Seedlings of the parents and F1, F2, and F3 progeny were evaluated for resistance to North American races of P. striiformis. Based on those evaluations, Carstens V has three genes for resistance to North American race CDL-21, two genes for resistance to races CDL-17, CDL-20, and CDL-29, and one gene for resistance to race CDL-27. The genes that confer resistance to race CDL-17 also confer resistance to race CDL-21. The three genes were either dominant or recessive depending upon the race used in the test and the cultivar used in the cross. None of the genes in Carstens V are the same as the genes for resistance in Cappelle Desprez, Chinese 166, Clement, Compair, Heines Peko, Hybrid 46, Minister, Nord Desprez, Triticum spelta album, and Vilmorin 23.