【Abstract】Objective To evaluate the security and efficiency of bedside interventional ultrasonography in the diagnosis and treatment of critically ill elderly patients. Methods A total of 85 critically ill elderly patients admitted in the Internal Medicine Ward of the Fujian Provincial Hospital from January 2013 to August 2015 were recruited in this study. With the aid of portable ultrasound system, bedside ultrasonography guiding biopsy or catheter drainage was performed on all of them. Results In the 15 patients undergoing biopsy, correct diagnoses were obtained in 13 cases, and the other 2 cases were unable to get a clear pathological diagnosis. In the group of catheter drainage (n=70), 23 cases of non-infectious effusion obtained patency drainage, and the corresponding symptoms disappeared thereafter. For the 47 cases of infectious effusion, their conditions were improved, and their symptoms, including temperature, heart rate, white blood cell count and depth of effusion, were significantly relieved after drainage (P<0.05). Medium dosage of bleeding was observed in 2 cases after thorax drainage. Conclusion Bedside interventional ultrasonography is safe and convenient in the diagnosis and treatment of the critically ill elderly patients, and has good value in clinical practice.