The paper analyses the experimental results of microbiological utilisation of mononitrotoluene and phenol at concentrations of 20, 50 and 70 mg/l by strains of Trichoderma fungi. According to the research, all the strains under study are able to grow in the presence of mononitrotoluene as the only source of nitrogen nutrition and phenol as the only source of carbon and energy. However, the strains have different sensitivity to changes in their concentration in the medium. Indeed, the strains under study are able to degrade mononitrotoluene and phenol in liquid medium. The maximum efficiency of mononitrotoluene biodegradation was 66% using Trichoderma koningii strain ‘TSL-06’, and that of phenol was 95% using Trichoderma harzianum strain ‘M99/5’. Based on the results, we selected perspective strains for biodegradation of mononitrotoluene and phenol by surface and deep cultivation methods, as well as for the development of a biopreparation based on fungi of the genus Trichoderma in an immersion biotechnological system.