Endolymphatic instillation of pharmaceutical products may accelerate sanation of trophic venous ulcers. The effectiveness of endolymphatic therapy needs to be estimated. Aim of the study. To estimate the effectiveness of endolymphatic medicamental therapy applied for the treatment of long-standing throphic venous ulcers. Material and methods. The study and control groups comprised a total of 58 patients. The patients of the study group (n=30) were treated by endolymphatic administration of sulidexide, selenase, and meropenem. Those in the control group were given traditional therapy alone. The two groups were compared in terms of dynamics of clinical symptoms at the early stages of the pathological process, results of bacterioloical, immunological, and cytological studies. Results. In the study group, the treatment resulted in a significant decrease in the frequency of occurrence of microflora in tissue biopsies. The bacterial growth was totally absent in 28 (93%) and 17 (61%) of the patients of the study and control groups respectively (p=0.004). Cytological studies revealed a rise in the number and activity of neutrophils in trophic ulcers in the patients of the study group. All of them exhibited a decrease in the depth of the ulcers, the earlier beginning of their edge epithelization, and the signs of active formation of the granulation tissue due to intensified vacuologenesis, mobilization of poorly differentiated (adventitious and fibroblastic) cells. These processes were accompanied by enhanced DNA synthesis and reproductive potential of the fibroblastic differon, in conjunction with activation of fibrillogenesis. Complete healing of 19 (63.3%) and 13 (46.5%) ulcers was documented in the study and control groups respectively after the termination of therapy (p=0.204). Conclusion. Endolymphatic administration of sulidexide, selenase, and meropenem stimulates the processes of reparative tissue regeneration which makes it possible to reduce the time needed to prepare the patients for the surgical intervention. The two groups were not significantly different in terms of the effectiveness of the treatment based on such criterion as the frequency of ulcer healing. The emerging tendency toward a higher frequency of the healing of trophic venous ulcers after endolymphatic therapy dictates the necessity of further studies.