After acid hydrolysis, both the hemicellulosic and cellulosic fractions of oil palm empty fruit bunch were fermented to lactic acid in a simultaneous detoxification, saccharification and co-fermentation process supplemented with 25 FPU Cellic® CTec2 cellulase per g cellulose, yielding 80.6 g/L of lactic acid with a productivity of 3.4 g/L/h. Neither pre-detoxification nor separation of fermentable sugars from lignin was required. These results indicate that B. coagulans JI12 is a promising strain for l-lactic acid production from lignocellulosic biomass.