Relevance. The incidence of malignant growths in the maxillofacial area has consistently increased over the years. Chemotherapy stands out as one of the most effective treatments for cancerous tumors. Chemotherapeutic drugs possess the capability to either inhibit the proliferation of malignant cells or cause damage to them. However, while acting on abnormal cells, cytostatic drugs also impact actively dividing cells in normal tissues, including the mucous membranes in the oral cavity. As a result, various complications are observed in every patient undergoing treatment for malignant neoplasms (MN), particularly chemotherapy (CT). The nature and severity of side effects undergo changes based on the specific drugs and cytostatic treatment regimen employed. Adverse reactions and side effects inherent to each drug category manifest at different points throughout a chemotherapy course and its aftermath. Oral mucosal (OM) complications, such as oral mucositis, may ensue as a consequence of CT side effects.Materials and methods. In order to assess the effectiveness of screening for OM disorders arising as side effects of chemotherapy, a study involving 37 patients undergoing chemotherapy for an underlying condition was conducted. The screening study comprised two stages: Stage I involved a quality-of-life assessment utilizing questionnaires developed by the authors, while Stage II entailed a clinical examination of the oral mucosa. The obtained data were subjected to statistical analysis methods. Variation statistics were employed to assess the likelihood of data errors.Results. Comprehensive OM diagnostics in patients undergoing chemotherapy for an underlying oncology condition enable the early identification of oral mucosal diseases and the prevention of complications. It is recommended to conduct a thorough clinical examination and employ toluidine blue staining during each follow-up visit. Any observed clinical or stained tissue changes, the emergence of new erythematous lesions, erosions, or ulcers may serve as indicators of malignant transformation.Conclusion. It is advisable to incorporate screening diagnostics into each patient's dental visit to proactively prevent the onset of various pathological conditions.