BACKGROUND Autogenous bone grafting is commonly used in reconstructive surgery but postoperative pain from the donor site can be severe, delaying early mobilisation and preventing discharge from hospital. METHODS An RCT of levobupivacaine infusion (16.25mg/h for 24h) of iliac crest wounds versus placebo. Postoperative pain was recorded immediately on returning to the ward, then at 1, 2, 3, 4, 5, 6h, morning and evening on subsequent days until discharge, and at the 7-day clinic appointment. Mobility was recorded twice daily and at 7days. RESULTS Of 46 evaluable patients, 25 were randomised to levobupivacaine and 21 to placebo. Mean pain scores for (i) average pain from initial assessment to 6h; (ii) 1day in the morning; (iii) 1day in the evening; (iv) at 2days; and (v) follow-up were all statistically significant in favour of lower pain scores in the levobupivicaine group (p-values all <0.01). Comparison between the study groups for mobility found 6 patients unable to get out of bed in the placebo group and none in the local anaesthetic group at the initial assessment (Fisher's exact test p-value=0.005), and 2 patients at 24h. Patients in the local anaesthetic group were always more mobile and this was statistically significant even at 7days for gait disturbance, limp, deviation of gait and unequalness of stride. There were no complications relating to the infusion system. CONCLUSIONS Local anaesthetic significantly reduced postoperative pain and improved mobility. We recommend that surgeons use a local anaesthetic infusion to improve the postoperative experience for their patients undergoing iliac crest grafting.