A 29-year-old pregnant woman was delivered by cesarean section under a combined spinal-epidural anesthesia. Thirty hours after an uneventful surgery, she complained of weakness in her lower extremities and developed fecal and urinary incontinence. Lumbosacral magnetic resonance imaging showed thickening and clumping of cauda equina nerve roots at L2-3 level, consistent with the diagnosis of arachnoiditis. The patient was included in an intense rehabilitation program with a diagnosis of cauda equina syndrome. Most of the symptoms resolved within a few days, but right side foot drop persisted for 2 years after the procedure. Because there was no other etiologies being noticed, we hypothesized that the hyperbaric bupivacaine neurotoxicity was likely to be the cause for this neurologic deficit.