In order to take advantage of the aquatic weed water hyacinth (Eichhornia crassipes) as lignocellulosic feedstock for the production of reducing sugars, a bromatological characterization of the leaves and stems of the plant was performed. Then, the effects of the sulfuric acid concentration (1 - 3% v/v), the concentration of solids (10 to 12.5% w/v) and the reaction time (15 - 25 min) at 121°C/15 psi in the production reducing sugars were studied by employing a central composite design. It was found that the acid concentration was the most significant variable. The optimal conditions were solids 11.25% p/v, H2SO4 2% v/v and 20 minute reaction time. These conditions yielded a concentration of reducing sugars of 33.3 g/L.