ifteen fertile rams (live weight 55.9 ± 1.21 kg, and 2.5-3 years old) were randomly allotted to three diets consisting of 0 (Control), 12.5 (PBP-12.5), and 25 % (PBP-25.5) pistachio byproducts (PBP) in dry matter. Sperm motility parameters were detrimentally affected in animals feeding on PBP-25% diet (P<0.05). Sperm concentration of C17-1, C22-6-n-3, C18-2-Cis and C22-6 n3 fatty acids decreased but that of C18-0 and C18-1-Cis fatty acids increased at the highest level of dietary PBP. The results indicated that 12.5% PBP in dry matter, as a cheap by-product, may be included in the ram diet for extended periods without any discernible detrimental effects on sperm characteristics. However, fertility trials need to be performed to substantiate this conclusion.