PURPOSE: To present our experience with spinal anesthesia in premature and former premature infants, and to focus on technical aspects and pitfalls enlightened with increasing experience. METHODS: The perioperative course of all premature and former premature infants below 60 weeks postconceptual age undergoing spinal anesthesia within an 35-month-period was analyzed. Lumbar puncture was performed while the patient was held seated at L4-5 or L5-S1. Anesthetics included hyperbaric tetracaine or bupivacaine, dose 1 mg/kg with adrenaline. The patients were positioned in the reverse Trendelenburg for 2-3 minutes, and later horizontally. RESULTS: Sixty seven infants (gestational age 30.1 +/- 3.6 weeks, postconceptual age 42.9 +/- 3.4, weight 3234 +/- 1165 grams) underwent spinal anesthesia and surgery. Thirty two had other diseases, including congenital heart (12), lung (15) brain pathology (8) and urological findings (6). Sixty five patients underwent hernia repair and two underwent pyloromyotomy. N2O was added in three infants, and two required general anesthesia. All were found to have lower limb motor blockade postoperatively. Intraoperatively, hypoxemia was diagnosed in two infants, short apnea in two cases and bradycardia in one. The apnea and hypoxemia episodes were successfully treated by reverse Trendelenburg positioning and bag and mask ventilation and the bradycardia that did not respond to tactile stimulation was relieved by atropine. Postoperatively, a short episode of apnea and hypoxemia (one patient) and hypoxemia (one patient) responded to free oxygen administration with/without tactile stimulation. Brief bradycardia (three infants) terminated without intervention. Supplementation and postoperative complication rates resembled previous studies. CONCLUSION: Successful spinal anesthesia in premature and former premature infants depends on close attention to preoperative assessment, patient positioning during and immediately after anesthetic induction, drug dosing and perioperative monitoring. A relatively high dose of local anesthetic should be administered.