Crohn's disease can cause intestinal strictures, perforations, fistulas, or abscesses. Although fistulas and abscesses are common complications of Crohn's disease, a presacral abscess with neuromuscular complications is very unusual. A delayed diagnosis and treatment may increase morbidity. The diagnosis is frequently delayed, because the clinical features of presacral abscess are variable and nonspecific. We experienced a case of a presacral abscess with bilateral sciatica in a 25-year-old male patient. He was diagnosed with Crohn's disease of the terminal ileum 2 months previously and has been managed with mesalazine. He visited our hospital due to pain in the buttocks and severe neuralgia in both thighs. We confirmed enteric fistulas, resulting in a presacral abscess, which extended symmetrically through both sciatic notches and the gluteus medius muscles. He was managed with antibiotics after a small bowel segmentectomy, right hemicolectomy, fistulectomy, and surgical drainage. The bilateral radicular pain resolved completely within 2 weeks of surgery. The patient has remained in remission and asymptomatic 1 year after surgery.