Objective: Conventionally spinal surgeries are done under general anaesthesia (GA). Plenty of literature is available on lumbar spine non-instrumented surgeries under spinal anaesthesia (SA) but handful of literature is there on lumbar spinal instrumented fusion surgeries under SA. We retrospectively analysed the data of 131 patients operated under SA and 108 patients under GA. Aim of the study was to evaluate the safety, advantages and disadvantages of doing lumbar spine instrumented fusion surgeries under SA. In time of COVID-19 pandemic, aerosol generating procedure like intubation, can be avoided if lumbar spine instrumented fusion surgeries are performed under SA. Methods: 239 patients aged between 20 and 79 years operated from January 2014 to December 2019 were included in this study. Indications for surgery were lumbar canal stenosis, degenerative or lytic spondylolisthesis. They underwent L4-L5 or L5-S1 fusion surgeries either TLIF or pedicle screw fixation postero lateral fusion (PLF) and decompression. Out of 239 patients,131 were operated under SA and 108 patients under GA. Heart rate, mean arterial pressure (MAP), blood loss, operating room time, post-op pain relief and need of analgesics, cost of surgery and anaesthesia related complications were analysed. Results: The study found significantly less blood loss (p<.05), less OR time, better post-op analgesia and lesser incidence of nausea and vomiting in SA (8.4%) than GA (29.6%). We observed average 10% cost reduction in SA. This study did not find any prone position related complication in regional anaesthesia but one transient brachial plexus palsy and one post-op shoulder pain in GA group. Conclusion: SA is a safe alternative to GA for lumbar spine instrumented fusion surgery with significant less blood loss, OR time, better post-op analgesia, average 10% overall cost reduction and no reported prone-position related complications.