Hereditary angioedema (HA) is a rare disorder characterized by recurrent angioedema attacks and autosomal dominant transmission. Plasma C1 occurs due to esterase inhibitor deficiency. Angioedema is most commonly seen in the extremities, oropharynx, and visceral organs. Intestinal mucosal edema can cause temporary obstruction and severe abdominal pain that can interfere with acute abdomen. It should be kept in mind that antihistamines, stereoids, androgens, FFP (Fresh frozen plasma) and C1 esterase inhibitors used in the treatment of these patients may also develop allergies and these drugs should be used with caution.  We aimed to present a 51 years old female patient (Figure-1) with a diagnosis of hereditary angioedema in our case which developed FFP (Fresh frozen plasma) allergy.