Use of epidural analgesia post-operatively in spinal surgery is becoming increasingly common. We have conducted a prospective study examining the side-effects associated with epidurals and the need for additional analgesia in 36 adult patients undergoing either lumbar spine decompression, lumbar spine fusion, or a combination of decompression and fusion. A mixture of bupivacaine and fentanyl was used for up to 72 hours post-operatively via an epidural catheter placed under direct vision at the time of surgery. All patients had urinary catheters inserted peri-operatively. 15 patients experienced one or more side-effects; 6 patients had a subjectively unpleasant sensory block, 3 patients developed a motor block, 4 patients had pruritus, 3 developed hypotension, and 2 had episodes of nausea or vomiting. All these features resolved upon reduction of the epidural rate or cessation of the epidural. All patients required additional oral analgesia at some point during their observation. There were no serious complications, such as infection, permanent neurological deficit, or cord compression. We conclude epidural analgesia following lumbar spine surgery is a safe practice, although the high rate of side-effects necessitates close observation by fully trained staff. It appears additional oral analgesia is required to obtain satisfactory levels of analgesia.