Background: Lower extremity surgeries performed in elderly people usually have high prevalence of peri-operative medical problems related to anaesthesia. The overall objective of peri-operative care of geriatric population is to fast recovery from anaesthesia and avoid functional decline. Objective: To compare the peri-operative pulmonary status of combined spinal epidural anaesthesia (CSEA) and spinal anaesthesia (SA) in geriatric patients underwent lower extremity surgeries. Methods: This prospective comparative study was conducted at Department of Anaesthesia, Analgesia and Intensive Care Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2016 to June 2018. A total of 70 geriatric cases that underwent lower extremity surgeries were included in this study. Cases were randomly allocated into two groups; 35 in Group A (CSEA) and 35 in Group B (SAB). The different outcome variables between the groups like-duration of anaesthesia, respiratory rates (RR), oxygen saturation (SpO 2