Hereditary angioedema is characterised by recurrent episodes of peri-orbital and peri-oral swelling which can cause an upper airway obstruction, abdominal pain, vomiting, diarrhoea, and even hypotensive collapse. This potentially fatal condition is frequently misdiagnosed; its early recognition and appropriate treatment are thus important. We report a familial cluster of hereditary angioedema in a Chinese family and describe the clinical course of two patients.