The aim of the study was to determine the possible use of the effluent, produced in the process of the anaerobic decomposition of organic substances, as a medium in the cultivation of microalgae Chlorella vulgaris. The characteristics of efficiency and kinetic of algae growth rate was determined. The scope included balancing of the effluent so as to provide an adequate level of nutrients required for algae growth. The effluent dilutions of 25%, 50%, 75% and 100% was tested. The effluent was supplemented with nutrients to create the same conditions as in the synthetic medium. The tested effluent can be used in the intensive cultivation of biomass of microalgae Chlorella vulgaris. The best results were obtained with the effluent dilution of 75%.