Simultaneous Saccharification, Filtration and Fermentation (SSFF) was developed for lignocellulosic ethanol production. In SSFF, pretreated lignocellulosic material is enzymatically hydrolyzed in a reactor, while the suspension is continuously pumped through a cross-flow membrane. The retentate goes back to the hydrolysis vessel, while a clear sugar-rich filtrate continuously perfuses through the fermentation vessel before it is pumped back to the hydrolysis vessel. The capacity and life span of the cross-flow filter module was examined for four weeks using enzymatically hydrolyzed slurry, initially with 14.4% suspended solids, without clogging or fouling. An ethanol yield of 85.0% of the theoretical yield was obtained in SSFF and a flocculating strain of Saccharomyces cerevisiae was successfully reused for 5 cultivations of SSFF.