An analysis of the clinical manifestations of complications caused by the toxic effect of chemotherapeutic drugs used in the treatment of malignant neoplasms was carried out. The variety of clinical symptoms that develop against the background of chemotherapy for malignant neoplasms leads to difficulties in differential diagnosis of a primary neurological disease and the identification of complications during treatment. The severity of these complications depends on a number of factors, including the drug used, its dosage and duration of use, the use of various methods of combination therapy and radiation methods, as well as the presence of comorbid pathology in patients. A clear understanding of the mechanisms of development of neurotoxicity and timely diagnosis of such conditions is a priority task of modern clinical medicine Modern methods of treating patients with malignant neoplasms should be based on a multidisciplinary medical approach, including a set of measures to prevent unwanted toxic effects of treatment, stratify individual mortality risks and develop methods of rehabilitation and medical examination.