Objective To investigate the value of bronchoscopic lavage in the treatment of severe pulmonary infection in the elderly.Methods A total of 118 elderly patients with severe pulmonary infection admitted in the Department of Respiratory Diseases and Intensive Care Unit of our hospital from May 2015 to May 2016 were recruited in this study. They were divided into observation group and control group according to the treatment they received, with 59 patients in each group. The patients in the control group were treated with routine therapy. The observation group was treated with bronchoscopic lavage besides the routine treatment. The baseline data and clinical efficacy (blood gas indices, time to normal body temperature and length of hospital stay) were compared between the 2 groups. SPSS statistics 19.0 was used to perform the statistical analysis. Student’s t test or Chi-square test was employed for different data types. Results There were no significant differences in baseline data between two groups before treatment (P>0.05). The blood gas indices changed significantly after the treatment in observation group compared with before treatment (PaO₂, SaO₂ and PaO₂/FiO₂ increased, while PaCO₂, CRP and WBC decreased). The levels of PaO₂[(86.30±4.27) vs (74.56±3.84) mmHg], SaO₂ [(94.06±1.38)% vs (88.56±1.25)%] and PaO₂/FiO₂ [(253.42±26.32) vs (227.34±20.01)] were significantly higher, while PaCO₂ [(45.57±1.46) vs (53.46±0.53) mmHg], CRP [(8.58±0.74) vs (12.52±0.96) mg/L], and WBC [(7.64±2.15)×10⁹ vs (10.38±2.58)×10⁹/L] were significantly lower in observation group than those in control group (all P<0.01). The observation group also had obviously shorter time to normal body temperature [(8.34±3.42) vs (11.52±5.03) d]and length of hospital stay [(15.32±3.28) vs (19.21±6.54) d] compared with the control group (P<0.05). The total effective ratewas 89.83% in the observation group, significantly higher than that in the control group (72.88%, P<0.05). All patients showed good tolerance to the surgery, and no serious complications occurred. Conclusion Bronchoalveolar lavage is effective in the treatment of severe pulmonary infection in the elderly, and has great clinical value.