Studies on the production of bioethanol from red algae (Gelidiella acerosa) by dilute acid pretreatment and simultaneous saccharification and fermentation were performed. The non-cellulosic compounds were significantly reduced during dilute acid pretreatment. Results obtained in simultaneous saccharification and fermentation showed that the ethanol yield was affected by the changes in pretreatment, liquid to solid ratio, enzyme concentration, and pH. Kinetic study was also performed with experimental value to analyze the production rate and their actual means of production process. The maximum 91.62% of theoretical yield of ethanol was obtained at 36 h of simultaneous saccharification and fermentation under optimized conditions.