Introduction. Nutritional support is an important component of multimodal cancer therapy. It is well known that proper nutrition supplemented by necessary nutrients can support muscles and their function, reduce the incidence and severity of complications associated with cancer therapy, and facilitate recovery. proper nutritional support is planned according to patient’s need for energy (30 kcal/kg body weight per day), protein (1.5 g protein/kg body weight per day), and eicosapentaenoic acid (2 g per day). Materials and methods. we analyzed the dynamics of nutritional status of 632 cancer patients treated in p.A. Herzen moscow Oncology Research Institute – a branch of the National medical Radiology Research Center, ministry of Health of Russia between 2019 and 2021. Study participants were divided into two groups: experimental (n = 316) and control (n = 316). patients in the experimental group received proper nutritional support. This study included patients with confirmed gastrointestinal cancers (esophageal and gastric), colon cancer, head and neck cancer, and lung cancer. Results. Nutritional therapy in the process of drug antitumor treatment has improved the trophological status of patients with tumors of the head and neck, lungs, upper gastrointestinal tract. As a result of the work, there was a tendency to increase the body weight of patients in these subgroups, whereas in the control group there was a statistically significant decrease in body weight compared to the initial indicators by 9.4; 9.5; 5.3 and 9.6 kg, respectively. Also, full clinical nutrition contributed to an increase in the level of total protein in patients with cancer of the upper gastrointestinal tract and colon and rectum by 4.0 and 3.7 g/l, respectively, at the level of statistical trend. The level of albumin significantly increased (by 6.6 g/l) only in patients with lung cancer. Improved nutritional status of patients during their systemic therapy ensured a 6 % reduction in the frequency of intercycle periods, a 0.2–3.4 % reduction in the need for dosage correction, and a 2.9–11.1 % increase in the completeness of cancer therapy stages (trend). Conclusion. Our findings suggest that additional specialized (oral or enteral) nutritional support during chemotherapy stabilizes body weight and its index, resulting, first of all, in improved tolerability of treatment. © 2022 National University of Science and Technology MISIS. All rights reserved.