This study was carried out at El Takamoly Poultry Project, Fayoum, Egypt,. A total number of 498 (450 breeder hens and 48 cocks) birds of Golden Montazah (GM) and Fayoumi (F) strains at 42 wks of age were used to evaluate the effects of two dietary levels of Se as Sel-Plex (0.1 or 0.2 mg/Kg diet) on breeder hens performance. Birds were divided randomly into 3 equal treatment groups of 83 birds each (75 breeder hen and 8 cock each). Birds were placed in 6 floor brooder pens, the 1st group was fed the basal diet, while the 2nd and 3rd groups were fed on the same diet but supplemented with one of the two levels (0.1 or 0.2 mg/Kg diet) of selenium (Se) as Sel-Plex. The experimental period was lasted for 23 weeks (from 42 to 65 wks of age).