The present work seeks to quantify the knowledge of two rural communities in the semi-arid region of the state of Pernambuco (northeastern Brazil) concerning two species of native medicinal plants: “aroeira do sertao”, ˜ Myracrodruon urundeuva (Engl.) Fr. All. (Anacardiaceae) and “angico”, Anadenanthera colubrina (Vell.) Brenan (Mimosaceae).