The effectiveness of phenol biodegradation as a function of the physicochemical parameters of the medium: temperature, pH, aeration, form of the inorganic source of nitrogen, presence of trivial substrates in the medium was studied. Using a two-factor dispersion analysis, the degree of influence of the various physicochemical parameters with regard to specificity of the biological factor was determined. Evaluation was made of the possibility to control the biodegrading process by means of physicochemical parameters of the medium.