Objective: Nowadays, microsurgical discectomy is being performed as an outpatient procedure. A retrospective chart review was done to document factors that delayed discharge or led to unanticipated admission., Methods: After Institutional Review Board approval, the hospital medical records of 106 patients who underwent microsurgical discectomy on an ambulatory basis were reviewed. All patients were operated upon by a single surgeon at the Toronto Western Hospital. Perioperative data were collected on specifically designed data sheets. All anesthetic and surgical factors that affected discharge were noted., Results: Of the 106 patients reviewed, only six required unanticipated admission. Two patients were admitted due to nausea and vomiting, one due to severe pain, one due to urinary retention and two were surgical causes (dural tear). Eight patients had delayed discharge. Anesthesia causes were severe nausea, severe pain, low oxygen saturation, sore throat and dry eyes. Two patients had surgical causes. The incidence of postoperative nausea was 61% and postoperative vomiting was 9.4%. Eighty patients (75.4%) complained of pain in the postanesthesia care unit. Of these, 33.9% had visual analogue pain scale scores more than 6., Conclusion: Ambulatory lumbar microdiscectomy can be carried out as an ambulatory procedure with an acceptably low unanticipated admission rate (5.7%). The percentage of patients with severe nausea (16%) and pain (33.9%) is high. Adequate perioperative pain management and effective control of nausea and vomiting may further improve the patients' experience after anesthesia for ambulatory microdiscectomy.