Hemicellulose is a valuable component of agro-food industrial wastes and used in various areas such as drug manufacture and food industry for encapsulation and emulsification. In this study, effects of raw material type, particle size, and extraction conditions (alkaline concentration, temperature, time) and methods (direct alkaline extraction, alkaline extraction after component removal and acidic extraction method) on hemicellulose yields were investigated. Sugar beet pulp and corn wastes were used as raw material. The alkaline method resulted in 40.2% pure extracts, while the acidic method gave only 27.4% purity in the same extraction conditions. The optimal extraction conditions were found as 30 degrees C temperature, 10% alkali (NaOH) and 24 h time (64.3%). It was also observed that removal of constituents such as fat, protein, starch and soluble sugar increased the purity of hemicellulose from 40.2% to 58.2% at the same conditions. The results indicated that using both low alkaline concentration and low temperature allows to recover higher-quality extracts.