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 (SpO2), end tidal CO2 (EtCO2), peak expiratory flow rate (PEFR), breath holding test (BHT), peri-operative side effects of anaesthesia and post-operative visual analogue score (VAS) were analyzed and compared by statistical tests. Results: The mean age, weight, BMI of Group A and Group B patients were not significantly different (p > 0.05). No significant differences were observed in duration of surgery, gender and ASA grade between the groups (p > 0.05). Mean duration of anaesthesia, mean time to achieve target level of sensory block and mean time to achieve complete motor block were significantly higher in Group A (p 2, PEFR and BHT of both groups were not significantly different (p > 0.05). Peri-operative side effects of anaesthesia and post-operative VAS were significantly less in group A patients (p < 0.05). Conclusion: Combined spinal epidural anaesthesia is effective and safe; produces stable peri-operative pulmonary status with prolonging analgesia and fewer side effects as compared to spinal anaesthesia in geriatric patients.