Hereditary angioedema (HAE) is a rare autosomal dominant disorder characterized by episodes of localized swelling, often of life-threatening severity. HAE due to C1 inhibitor (C1-INH) deficiency is common and is divided into types 1 and 2, but HAE with normal C1-INH is exceedingly rare. Herein, we describe the case of a patient with HAE with normal C1-INH undergoing orthognathic surgery. A 24-year-old woman came to our hospital with a diagnosed jaw deformity and commenced preoperative orthodontic treatment before scheduled orthognathic surgery. During the preoperative period, she experienced mild hoarseness. The hoarseness worsened, and computed tomography revealed mild laryngeal edema. Serum C1-INH, C3, C4, and CH50 levels were normal. Her younger sister had reportedly experienced a similar episode of lip edema previously. These findings supported a diagnosis of HAE with normal C1-INH. She underwent orthognathic surgery in close consultation with a hematologist and anesthesiologist at the age of 33 years. The surgery was completed without complications. She reported throat tightness 4 days after surgery, although her facial swelling was consistent with the procedure performed and was not remarkable. Concentrated C1-INH was administered, and the throat tightness slowly resolved within approximately 1 hour. Twenty-five days after surgery, she was discharged with reduced facial swelling. In the present case, orthognathic surgery was performed successfully in a patient with the exceedingly rare condition of HAE with normal C1-INH, in close consultation with a hematologist and an anesthesiologist. Postoperative throat tightness was successfully treated via the administration of concentrated C1-INH. Concentrated C1-INH administration can be considered in patients with HAE and normal C1-INH who experience angioedemic attack, keeping in mind that it may be slow to take effect.