Angioedema is a rare, but important effect of arterial hypertension treatment with drugs which inhibit angiotensin-converting enzyme. Usually, it develops in the first week of therapy, but some atypical cases of the development of angioedema after several months to few years after the onset of the therapy have been reported. Undesired reactions caused by these drugs are probably not allergic, but they are caused by pharmacological effect of these drugs in persons with risk of allergic reaction. In this paper we present some patients with angioedema.