A 33-year-old man who had recently undergone surgery for cervical spondylotic myelopathy was prescribed pregabalin for neuralgia, and the dose was increased to 600 mg/day during hospitalization. However, the patient was diagnosed with a Clostridium difficile infection on day 34 after admission. A complete blood count showed agranulocytosis (neutrophil count: 105/μL). We did not observe any changes in vital signs, a relative increase in band cells, or intestinal edema. The patient's agranulocytosis resolved after withdrawing pregabalin. This is the first reported case of agranulocytosis associated with pregabalin. Periodic monitoring of the white blood cell count is therefore considered to be useful in patients receiving high-dose pregabalin therapy.