In this study, the acceptability of whole pistachio culls, instead of hay, were investigated. For this reason, 6 lambs were used and offered diets containing concentrate and roughage in a 80:20 ratio. Pistachio culls were added into roughage and roughage were 1 00 % hay (Control), 70 % hay + 30% pistachio culls (Treatment 1) and 50 % hay+ 50 % pistachio culls (Treatment 2). The effects of diets on ruminal fermentation and digestibility of nutrients were evaluated. Ruminal parameters (pH, volatile fatty acids, NH3 concentrations) did not differ (p>0.05) among groups in ruminal fluid taken at 1 h and 4 h postfeeding. Digestibilities of nutrients were not significant beetwen groups (p>0.05).