Background. One of the unsolved problems of treatment of patients with chronic wounds in outpatient conditions is low efficiency of the used treatment methods, especially it concerns patients with chronic deep wounds and bone tissue involvement in the process. Description of a clinical case. Patient F., 77 years old, came for outpatient treatment in April 2022 with local necrosis in the area of the 1st toe of the left foot. The main diagnosis: atherosclerosis of peripheral vessels of the lower extremities. Multifocal atherosclerosis. Occlusion of the superficial femoral and hamstring arteries, diffuse lesion of the arteries of the lower leg on the left. Chronic arterial insufficiency of the 4th degree. Attempts of revascularisation of the left lower limb. Limited gangrene (Wagner-IV) of the 1st toe of the left foot. Associated diseases: insulin-dependent type 2 diabetes mellitus (more than 30 years of experience). Diabetic polyneuropathy, sensorimotor, pronounced. Diabetic foot syndrome, neurotrophic form. Hypertensive disease 3st. CCN1. Bronchial asthma. Treatment. At the first stage of local treatment we took a wait-and-see tactics during 2 weeks. At the second stage of local treatment we used microsurgical technique of debridement of the affected surface in combination with the method of tiered dressings according to the technology patented by one of the authors. The third stage of treatment consisted of microsurgical treatment of the bone surface in the wound area, combined with the use of autolytic agents, at the same time conditioned medium from human placental mesenchymal stem cell cultures (PB-MSCs) was used in the area of granulation. Complete closure of the open bone fragment was observed after 12 months from the beginning of treatment in outpatient conditions. Conclusion. We have demonstrated the effectiveness of treatment with CS-MSCs for chronic wounds with open bone surfaces in the area of distal parts of the toes of the foot.