Descriptive case report.To report spinopelvic dissociation as a complication of autogenous bone graft harvest with the use of an acetabular reamer.Iliac crest bone graft harvest has been previously described in orthopedic literature with overall complication rates of 0% to 39%. Complications are inconsistently separated into "minor" and "major" groups, commonly reporting hematoma, infection, and injury to the superior gluteal artery or nerve. No reports of spinopelvic dissociation, a well known injury in the traumatic setting, have been reported.We report the case of 1 patient who presented with spinopelvic dissociation after autogenous bone graft harvest with the use of an acetabular reamer.We present a unique case in which fracture through the reamer harvesting site led to complete disruption of the posterior pelvic ring on the operative side. Subsequent attempted closed management led to failure through the osteoporotic anterior pelvic ring on the operative side and the posterior pelvic ring on the contralateral side, leading to progressive instability, disability, and pain. This was successfully addressed with lumbopelvic fusion and 2-year follow-up is presented.The potential hazard of acetabular reamer bone graft harvest is discussed, and primary operative fixation of harvest-related fractures is suggested.