Objective To explore the significance of serum soluble urokinase-type plasminogen activator receptor (suPAR), pentraxin 3 (PTX3) and neutrophil-to-lymphocyte ratio (NLR) in reflecting the disease severity and prognosis in the elderly patients with community-acquired pneumonia (CAP). Methods A total of 146 elderly CAP patients admitted to Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from June 2021 to June 2022 were included as the study subjects. Serum suPAR, PTX3 and NLR levels on admission were measured and compared between severe CAP patients (severs CAP group, n=50) and non-severe CAP patients (non-severe CAP group, n=96). Serum suPAR, PTX3, NLR, CURB-65 score and PSI score were compared between death group (n=12) and survival group (n=134). Data analysis was performed with SPSS statistics 19.0. According to the data types, t test, Mann-Whitney U test or Chi-square test was used for between-group comparison. Pearson linear correlation analysis was used to analyze the correlation between serum suPAR, PTX3, NLR levels and CURB-65 score, pneumonia severity index (PSI) score, C-reactive protein (CRP) and procalcitonin (PCT) in the elderly CAP patients. Multivariate logistic regression analysis was used to analyze the factors affecting disease severity in them, and receiver operating characteristic (ROC) curve was drawn to evaluate the efficiency of each indicator on predicting poor prognosis in them. Results There were statistically significant differences between severe CAP group and non-severe CAP group (P<0.05) in white blood cell (WBC) [(10.43±2.16)×10⁹/L vs (7.65±1.83)×10⁹/L], CRP [(84.63±15.37) mg/L vs (41.74±10.25) mg/L], PCT [(0.53±0.15) μg/L vs (0.12±0.02) μg/L], neutrophil ratio [(84.15±18.65)% vs (73.15±14.69)%], lymphocyte ratio [(8.44±2.15)% vs (15.74±2.36)%], NLR [(9.97±1.86) vs (4.65±1.19)], serum suPAR [(5.31±1.16) ng/ml vs (2.38±0.36) ng/ml], PTX3 [(12.34±2.73) ng/ml vs (6.41±1.57) ng/ml], CURB-65 score [(2.13±0.75) vs (1.36±0.21)] and PSI score [(93.47±25.37) vs (60.43±19.42)]. Pearson correlation analysis showed that serum suPAR, PTX3 and NLR were positively correlated with CURB-65 score (r=0.396,0.281,0.325; P<0.05) and PSI score (r=0.279,0.276,0.246; P<0.05). Serum suPAR and NLR were positively correlated with CRP level (r=0.349,0.306; P<0.05). Serum PTX3 was positively correlated with PCT level (r=0.321; P<0.05). Multivariate logistic regression analysis suggested that NLR (OR=1.551,95%CI 1.188-2.025), suPAR (OR=1.765,95%CI 1.223-2.546) and PTX3 (OR=1.964,95%CI 1.159-3.328) were factors affecting disease severity in the elderly CAP patients. Totally, 12 patients (8.22%) died within 30 d. Serum suPAR, PTX3, NLR, CURB-65 score and PSI score in death group were higher than those in survival group, the differences were statistical significance (P<0.05). ROC curve showed that serum suPAR (AUC=0.809,95%CI 0.719-0.899), PTX3 (AUC=0.788,95%CI 0.631-0.905), NLR (AUC=0.836,95%CI 0.727-0.945) and PSI (AUC=0.714,95%CI 0.619-0.849) were of some value in predicting death in CAP patients, and the predicting efficiency of serum suPAR, PTX3 and NLR was higher than that of CURB-65 score and PSI score. Conclusion Serum suPAR, PTX3 and NLR have certain value in reflecting the disease severity and prognosis in the elderly CAP patients.