The last 15 years has been actively developing methods of evaluation of trace elements in the human body for the hair analysis. The content of trace elements in hair reflects their level in the human body, and is an integral indicator characterizing his element status. Purpose: study of trace elements in patients with second-stage breast cancer. Object and Methods: To determine the content of trace elements studied 30 women with hair 2nd stage breast cancer who were treated at the Republican Specialized Scientific and Practical Medical Center of Oncology and Radiology, Ministry of Health of the Republic of Uzbekistan in 2016. The study of hair samples for content of trace elements (calcium, potassium, sodium , chlorine, iron, zinc, copper, manganese, cobalt, chromium, selenium, iodine, bromine) was conducted in the laboratory analysis of the activation of the Institute of nuclear physics of Uzbekistan Academy of Sciences (Institute of nuclear physics, Academy of Sciences of Uzbekistan), instrumental neutron activation analysis. 95% confidence interval (CI) of the received data on the micronutrient content of the in hair of patients compared with reference values for the population of Uzbekistan, received at the INP as RUz (Tashkent). Results: showed a reduction of iron, zinc, copper, cobalt and high content of chlorine as compared with the reference values. Conclusions: Studies have shown the possibility of using the results for the primary prevention and identification of risk groups among women, as well as the usefulness of the correction of specialized treatment medication with microelement complexes.