This investigation was carried out at the experimental farm of Sakha Agricultural Research Station, during wheat growing seasons from 2009 to 2011. The objectives were to study the inheritance of adult plant resistance to stripe rust Puccinia striiformis f. sp. tritici [Pst] in the two Egyptian bread wheat cultivars Giza160 and Giza168 and identification of the most effective Yr genes under study. Two Egyptian wheat cultivars (Triticum aestivum L.) i.e., Giza168 (resistant) and Giza160 (susceptible) to strip rust were crossed to four monogenic lines (Yr's) i.e., Kalyansona, Lee, Compair, and Jupateco R, which having strip rust resistance Yr's gene(s); Yr2, Yr7, Yr8 and Yr18+, respectively. Yellow rust reaction of the two cultivars and monogenic lines and their F₁ and F₂ populations were scored under field conditions. Artificial inoculation was done using mixture of physiological races of [Pst] at adult stage. Dominance of yellow rust resistance over susceptibility was noticed in most cases (in four out of five resistant by susceptible crosses). Segregation in the F₂'s population showed the presence of two to three gene pairs controlling plant reaction against the [Pst]. The Yr8 gene had high effectiveness of conferring resistance against [Pst] under this investigation. Meanwhile, broad sense heritability estimates was high, thus early generation selection for stripe rust resistance could be effective for wheat improving for this character.