BACKGROUND The purpose of the present study was to evaluate the effect of leptin and leptin receptor (LEPR) expression on the efficacy of neoadjuvant chemotherapy in breast cancer. MATERIAL AND METHODS There were 325 breast cancer patients with complete data enrolled in this study. Patients were categorized into 3 groups: pathological complete response group, non-pathological complete response group, and progressive disease group. Immunohistochemistry was performed to determine leptin and its receptor LEPR expression levels that were compared among the 3 groups. RESULTS Compared with the non-pathological complete response group, patients in the pathological complete response group had increased leptin and LEPR expression, although the difference was not statistically significant (P=0.194, P=0.110). In addition, the expression of leptin and LEPR in the pathological complete response group was also higher than that in the progressive disease group, and the difference of LEPR expression was statistically significant (P=0.008) while the leptin expression was not (P=0.065). There were more HER2+ breast cancer patients in the pathological complete response group categorized into strong positive, and positive expression of leptin and LEPR compared with the progressive disease group (P<0.05). There were significant differences of leptin and LEPR expression among breast cancer patients under different molecular subtypes HER2+, HR+, and triple negative, in which the triple negative patients had the highest expression of leptin and LEPR. In addition, patients in the progressive disease group had high and low expression of leptin and LEPR: 13.25% versus 11.32% and 13.1% versus 10.42% respectively. CONCLUSIONS Overexpression of leptin and LEPR improved the therapeutic efficacy of neoadjuvant chemotherapy for patients with breast cancer, especially for those with HER2+ subtype. Overexpression of leptin and LEPR was distinct among the different molecular subtypes of breast cancer, suggesting a certain predictive value for breast cancer prognosis.