Breast cancer is the most common diagnosis established in women with malignant tumors. The purpose is to investigate the blood contents of adiponectin and leptin in women with breast cancer and obesity. A total of 140 women aged 40-50 were examined. Group 1 included 70 women from classes 1 or 2 obesity. Group 2 included 70 women with stage 1 or 2 breast cancer and classes 1 or 2 obesity. The control group included 30 apparently healthy women, with mean age of 42.5 ± 2.5 years. Statistical processing of the results obtained was performed using Statistica. Groups 1 and 2 were statistically significantly different from each other across all parameters, except for leptin resistance. In group 2, the course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis, which manifests as a 1.94-fold decrease in the blood content of adiponectin (P < 0.05), a 4.14-fold increase in the blood content of leptin (P < 0.05), and an 8.00-fold increase in the leptin/adiponectin ratio (P < 0.05). Poorly differentiated breast tumors exhibit a more pronounced imbalance in the blood levels of adipocytokines. Thus, the serum content of leptin in women with poorly differentiated tumors (G3) was 1.79 times (P < 0.05) higher than in women with moderately differentiated tumors (G2). The course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis and decreased adiponectin concentration in the blood.