Sweet sorghum carbohydrates were simultaneously saccharified and fermented to ethanol by a mixed culture of Fusarium oxysporum and Saccharomyces cerevisiae in a bioreactor : Fusarium oxysporum was grown aerobically for the production of the enzymes necessary for the saccharification of sorghum cellulose and hemicellulose. Saccharomyces cerevisiae, together with F. oxysporum. converted the soluble sugars to ethanol. Three batches of sorghum were wed, harvested at different periods of the year. The optimum yield of bioconversion and ethanol concentration was 5.2-8.4 g ethanol/100 g of fresh sorghum and 3.5-4.9% (w/v), respectively, depending on the composition of sorghum stalks. In all experiments, the ethanol yield exceeded the theoretical, based on soluble sugars, by 20.0-32.1% due to bioconversion of polysaccharides to ethanol.