Citrus peel wastes are partly used for cattle feed either fresh or after ensilage or dehydration, but considerable quantity of citrus pulp in the fresh state is lost as a result of the difficulty of rapidly disposing a large quantity of the wastes in a faily short period of time. Citrus peel wastes are a potential foodstock for production of bioethanol due to their high. carbohydrate content. Their also contain insoluble polysaccharide fractions, such as cellulose, hemicellulose, and pectin, which can be enzymatically hydrolyzed to sugar by using a combination of hydrolytic enzymes.The aim of this work was the optimization of alcohol production through a biologic pretreatment (BP) and a simultaneous enzymatic saccharification and fermentation process (SSF) of orange wastes. The BP was made in solid cultures with T. harzianum and P. Ostreatus. The SSF was made with T.harzianum’s cellulase and K.marxianus as a fermenting microorganism. The total reducing sugars were analyzed with the DNS method.