Background Pneumonia is the most common infectious disease in patients undergoing maintenance hemodialysis (MHD). The aim of this study is to determine the possible predictive value of thoracic fluid content (TFC) for pneumonia in this population. Method Clinical data were recorded for 1412 MHD patients who were hospitalized for certain comorbidities or complications. Each patient underwent an impedance cardiography (ICG) examination before next dialysis session after admission. Patients were divided into Having-, Will-have-, and Non-pneumonia groups based on whether they had pneumonia at the time of ICG examination after the admission and within five months after the examination. Hemodynamic parameters and other clinical data were compared and analyzed. Results Patients who were going to develop pneumonia were older, and had a higher proportion of diabetes, poorer nutritional status, a higher level of inflammatory, poorer cardiac function, and more fluid volume load than those who did not develop pneumonia. Multivariate binary logistic analysis revealed that for each 1/KΩ increase in TFC and 1 increase in neutrophil-to-lymphocyte ratio (NLR), the risk of the development of pneumonia increased by 3.1% (p ˂ 0.01) and 7.2% (p = 0.035), respectively, whereas for each 1 g/L increase in hemoglobin and 1 g/L increase in serum albumin, the risk of the development of pneumonia decreased by 1.3% (p = 0.034) and 5% (p = 0.048), respectively. Conclusions TFC, NLR, hemoglobin, and serum albumin were independent risk factors for the development of pneumonia in MHD patients. Given the advantages of ICG, TFC can be used clinically as a helpful predictor of pneumonia in MHD patients.