Rhizopus oryzae NRRL, 395 produces optically pure L(+)-lactic acid that is highly preferred for the production of environmentally benign polymers. With xylose as the carbon source for cultivation, it can be self-immobilized as pellets with a size of about 1 mm. Repeated usage of the same pellets by transferring them into fresh media every time when the glucose was exhausted over a period of 22 d yielded 1742 or 2001 g/L lactic acid total (based on 100-mL working volume) depending on the media used. Lactic acid is known to be a strong inhibitor for both growth and production, and it can be removed continuously by the adsorption on the PVP resin. With the fermenter-adsorber system, the fermentation can be performed as effectively as the ones with added neutralizing agents, such as calcium carbonate and sodium hydroxide. One problem of the fermenter-adsorber system is that lower production was obtained than in shake flasks; hence, proper reactor design is necessary to improve the process.