The problem of treating elderly patients is one of the most pressing in modern clinical medicine. Colorectal cancer is one of the main causes of mortality from malignant neoplasms in Russia and other developed countries. At the same time, the incidence of tumors of the colon and rectum steadily increases with age. Before starting treatment for elderly patients, it is necessary to carefully weigh the potential risks and the possibility of achieving positive results of antitumor therapy. Objective: To summarize the literature on the use of a comprehensive geriatric assessment, including the Cancer and Aging Research Group (CARG) toxicity assessment, to predict the risk of adverse events during anticancer drug treatment in elderly patients diagnosed with colorectal cancer. Materials and methods: The search for scientific sources was carried out in PubMed / Medline / UpToDate using the following keywords: “malignant tumors”, “metastatic colorectal cancer”, “senile age”, “antitumor drug therapy”. The time horizon covered 2016–2023. Using a time filter, the most relevant and innovative research papers on the issues of chemotherapy treatment of elderly and senile patients were selected. Results: Most current evidence demonstrates the importance of performing a comprehensive geriatric assessment (CGA), Cancer and Aging Research Group (CARG) toxicity assessment in elderly and geriatric patients. Information obtained from geriatric assessment should be used to predict and manage treatment toxicity. And also for assessing and predicting overall survival. Activities based on CGA can reduce the toxicity of chemotherapy, improve the quality of life of patients, and increase compliance with medical recommendations. Undoubtedly, a comprehensive geriatric assessment (CGA) can help achieve the necessary balance between the potential effectiveness and adverse events of chemotherapy. The choice of treatment tactics for an elderly and senile cancer patient should be based on the patient’s functional status (PS), general somatic status according to the ECOG scale, and the risk of toxicity according to the CARG scale. In the presence of colorectal cancer, patients with good functional status who need antitumor systemic effects can be prescribed polychemotherapy with FOLFOX, XELOX, FOLFIRI doublets with the addition of targeted drugs: bevacizumab or cetuximab (depending on the results of gene profiling of the tumor). Patients who are not candidates for polychemotherapy in standard doses, who have a general somatic status on the ECOG scale of 1-2 and an average risk of developing toxicity of grade 3 on the CARG scale, can undergo PCT with FOLFOX, XELOX, FOLFIRI doublets with a reduction in the starting dose by 20%, or monochemotherapy with antimetabolites: capecitabine, 5-fluorouracil; topoisomerase I inhibitor irinotecan. Patients with poor functional status, general somatic status on the ECOG scale 3-4, and a high risk of developing toxicity on the CARG scale are not candidates for systemic combination chemotherapy. Particular attention should be paid to maintenance therapy in this subgroup of patients. However, if the decrease in PS level is directly related to malignancy and PS ≥2, the possibility of monochemotherapy by infusion of a combination of 5-fluorouracil and leucovorin FU/LV can be evaluated.