The objective of this study was to determine the effect of different levels of sesame wastes (SW) on performance, milk composition and blood metabolites in lactating dairy cows. In this order, eight multiparous Holstein dairy cows were used in a replicated 4×4 Latin square design in four periods of 21 days. Treatments were control (no Sesame meal supplementation), and supplemented with 5, 10 and 15 % (dry matter [DM] basis) Sesame wastes respectively. Each period of experiments included 14 days for adaptation to diets and 7days for sampling. Cows were fed as total mix ration (TMR). The results showed that DMI, milk lactose, MUN, BUN and blood glucose and cholesterol were not affected by experimental diets (P>0.05). Nevertheless, milk yield average, milk fat, protein percentage, milk TS, SNF percentage, blood Ca and TG showed significant differences (P<0.05) between treatments and was the highest in control treatment. In addition, dry matter (DM) and organic matter (OM) digestibility were affected by adding sesame waste in diets (P<0.05) and was the highest in control treatment. Generally, showed that sesame waste (as a byproduct) has not obviously positive effects in cows nutrition.