The aim of the project was to analyze the potential application of biodegradable wastes from markets and restaurants as the feedstock for lactic acid production by lactic fermentation. Lactic acid is widely used for the production of medical biopolymers, packaging, synthetic fibers and clothing. Another major use of lactic acid includes food, tanning and cosmetic industries. Being regarded as a kind of organic recycling, lactic acid production from organic wastes is given high priority in the strategies for waste processing and management. The organic waste samples made use of in both laboratory and full-scale investigations were inoculated with milk bacteria (Pediococcus acidilactici, Lactobacillus paracasei, Lactococcus lactis) that are present in the commercial product Bonsilage Forte made by Lactosan. Laboratory investigations revealed that the optimal temperature for lactic fermentation was 37. Another finding produced by the study was that the efficiency of the process decreased notably as the dilution of the wastes with water increased (from 1:1 to 1:10). Consideration was also given to the problem of how the addition of lime or soda lye, the filling of the gas space in the bioreactor with inert gas (nitrogen) and oxygen, and the dosage of glucose influence the course of the process and the decomposition of the lactic acid. The results of full-scale investigations (carried out in a bioreactor of a 30 m3 operating volume) were promising; lactic acid concentration remained constant at a high dilution of the waste with water. Further investigations will focus on the development of an efficient method for the separation of lactic acid from the liquid product of the lactic fermentation of organic wastes.