Objective To determine the curative effect of bronchoalveolar lavage (BAL) on severe pneumonia in the elderly patients. Methods A total of 82 elderly patients suffering from severe pneumonia in Department of Respiratory Diseases in our hospital from January 2011 to March 2015 were prospectively recruited in this study, and they were randomized into 2 groups, observation group [n＝41, (76.7±8.8) years old] and control group [n＝41, (76.3±9.3) years old]. The former group was treated by conventional treatment and BAL, while the latter by conventional treatment only. Their clinical outcomes, indices of arterial blood gas analysis, and scores of acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) were compared between the 2 groups. Results In 7d after the treatment, the total effective rate was significantly higher in observation group than in the control group (87.8% vs 63.4%, P＜0.05). The levels of oxygen saturation (SaO2), partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2) and APACHEⅡ scores were significantly improved in the 2 groups after 3 days’ treatment, and the improvement was more obvious in the observation group than in the control group (P＜0.05). Conclusion BAL as an adjuvant treatment significantly improves curative effect and reduces mortality in the elderly patients with severe pneumonia.