Production of L(+)-lactic acid by Rhizopus oryzae NRRL 395 was studied in solid medium on sugar-cane bagasse impregnated with a nutrient solution containing glucose and CaCO3. A comparative study was undertaken in submerged and solid-state cultures. The optimal concentrations in glucose were 120 g/l in liquid culture and 180 g/l in solid-state fermentation corresponding to production of L(+)-lactic acid of 93.8 and 137.0 g/l, respectively. The productivity was 1.38 g/l per hour in liquid medium and 1.43 g/l per hour in solid medium. However, the fermentation yield was about 77% whatever the medium. These figures are significant for L(+)-lactic acid production.