Hereditary angioedema (HAE) due to C1-INH deficiency (C1-INH-HAE) is an autosomal dominant inherited disease characterized by recurrent skin and mucosa swellings that commonly involve the extremities, intestines, face, genital area and upper airways. Dental procedures are important attack triggers in C1-INH-HAE patients. Attacks following dental procedures are commonly localized to the face and larynx. Laryngeal edema can cause death by asphyxiation.A 48-year-old female patient was admitted to our hospital because of the excessive accumulation of calculus on the teeth which was noticed during routine dental examination. At the oral examination calcified dental plaque, bleeding by gingival probing, and discoloration of the teeth #31-32 were detected. By radiographic and clinical findings radicular cyst pre-diagnosis was made, and it was decided to enucleate the cyst.However, the patient’s medical history revealed that she was diagnosed with C1-INH-HAE at the age of 40. To prevent possible facial and laryngeal edema, 1000 units of C1 inhibitor concentration was given 1 hour before the procedure. Under local anesthesia, the lesion was totally enucleated with its capsule. The risk of having attack after tooth extraction is about 37.5% and nearly 1/3 of these attacks are associated with laryngeal edema in patients with C1-INH-HAE. However, prophylaxis with C1 inhibitor concentration led to a 44.1% reduction in angioedema attacks on a per-patient basis. With this case, we wantedto draw attention to the importance of questioning the patient and his/her family for recurrent nonpruritic skin and mucosa swelling and abdominal pain attacks before surgical interventions to the mouth, neck, and throat area.