We report the case of a 46 year-old woman presenting an acquired angioedema. Angioedema is an C1 inhibitor deficiency. Patients present recurrent non inflammatory swelling of the head and extremities and recurrent attacks of severe abdominal pain. This clinical presentation is non specific : investigation of complement is useful for diagnosis. Laboratory testing show low serum levels of C4 with normal levels of C3. Low C1 esterase inhibitor confirm the diagnosis. If acquired angioedema, a cause must be searched.