40 patients undergoing posterior spinal fusion with posterior iliac crest bone graft were randomized to receive either a single administration of bupivacaine or placebo at the donor site. The purpose of this study was to evaluate long-term pain management between the two groups. Results at 20 weeks indicated significantly lower pain (visual analogue scale; VAS) at rest scores in favour of patients treated with bupivacaine over placebo. Numeric rating scale (NRS) scores for worst, average, and current pain were comparable between groups at 20 weeks. Health quality and functional outcomes were similar between groups. Patient satisfaction was higher in the bupivacaine group, although statistical significance was not reached.