The objective of the research study was to assess the ability of newly isolated Rhizopus oryzae strains to produce L (+) lactic acid. 40 isolates were tested and a significant lactic acid concentration was found in the post-culture filtrates of 20 isolates. Those strains were assigned to the Rhizopus oryzae species, whereas the rest of the strains, including species belonging to the Rhizopus stolonifer species, did not show these abilities. The lactic acid concentration levels in the filtrates varied depending on the used strain of the fungus and the type of carbon source. The highest lactic acid concentration, 74.06 g/L, was determined in a post-culture filtrate of R-42 Rhizopus oryzae strain, in a medium containing 100 g/L of glucose. The highest yield of lactic acid, 89.4 %, and a productivity close to 0.5 g/Lxh were also obtained after cultivation of R-42 R. oryzae strain in a medium containing 50 g/L of glucose. Slightly lower values were reported when mannose or fructose were used as a carbon source. Yet, significantly lower values were obtained when the carbon source was a xylose or a starch. Of all the strains tested only 5 were able to grow and produce lactic acid in a medium with sucrose. The best R-83 R. oryzae strain was characterized by a high yield production of lactic acid amounting to nearly 90 % in a medium supplemented with 50 g/L of sucrose. All the tested strains produced L(+) lactic acid.