The objective of the present study was to analyse the effectiveness of the methods for obtaining the functional suction impressions taking into consideration the peculiar features of the denture-supporting area of the toothless jaws. Material and methods. This clinical study involved 38 patients allocated to two groups. In group 1, the functional suction impressions were prepared by the conventional technique. In group 2, the modified method for making impressions of the toothless jaws with the use of the «alignment» trays was employed. Results and discussion. The estimation of the masticatory efficiency and prosthetic adaptation time as well as dynamometric comparison of the degree of denture fixation revealed better qualitative results in the patients of the second group. Conclusion. The results of this study give evidence of the positive influence of using the «alignment» trays for obtaining the functional impressions of toothless jaws on a number of clinical characteristics in the patients under the unfavourable conditions for dental prosthetics.