Abstract: OBJECTIVE To study the effects and clinical significance of pulmonary infection on peripheral blood monocyte Toll-like receptor 4（TLR4） and nuclear factor-κB（NF-κB） signaling pathway in elderly patients with chronic heart failure（CHF）. METHODS A cross-sectional study was performed on 68 elderly patients with CHF and pulmonary infection, which was in the infection group, 62 patients with CHF but without pulmonary infection divided in the CHF group and 71 healthy subjects with physical examination as the control group in the Second Department of Cardiovascular Medicine of Zhengzhou TCM Hospital between Jul 2016 and Jul 2020. The basic data were collected among the three groups, and the treatment and nursing plans in the CHF group and infection group were recorded in detail. The expression levels of peripheral blood monocyte TLR4 and NF-κB, levels of inflammatory factors of serum interleukin-4（IL-4）, IL-6 and tumor necrosis factor-α（TNF-α） and myocardial injury markers of serum creatine kinase isoenzyme（CK-MB） and cardiac troponin I（cTnI） among the three groups were detected and compared. RESULTS The levels of serum CK-MB, cTnI, IL-4, IL-6 and TNF-αin the infection group and CHF group were significantly higher than those in the control group; the levels in the infection group were significantly higher than those in the CHF group（P＜0.05）. The expression levels of peripheral blood monocyte TLR4 and NF-κB in the infection group and CHF group were significantly higher than those in the control group, and the levels in the infection group were significantly higher than those in the CHF group（P＜0.05）. CONCLUSION The activation of TLR4/NF-κB signaling pathway and the expression levels of inflammatory factors such as IL-4, IL-6 and TNF-α are increased in elderly patients with CHF complicated with pulmonary infection, which may lead to the aggravation of the body’s inflammatory response and cardiac function injury of patients.