Colonic pseudo-obstruction (CPO) is a syndrome characterized by obstructive symptoms and signs without mechanical obstruction. Parkinson's disease is one of the various clinical situations developing CPO. Recently, one study group reported that neostigmine was significantly more effective than placebo in rapidly decreasing colonic dilatation in the majority of patients with acute CPO. We experienced a 69-year-old male patient with Parkinson's disease who complained abdominal distension. There was a marked colonic dilatation on plain abdominal radiographs without mechanical obstruction. Colonic dilatation failed to improve with conservative management. Immediate clinical response was achieved after patient received 2.0 mg of neostigmine intravenously under monitoring by electrocardiography. One month later, he had recurrent colonic dilatation, but no clinical response to second administration of neostigmine, leading to colonic decompression. After a third recurrence of colonic dilatation, the patient was refractory to conservative management, and he underwent surgical treatment.