Extrinsic allergic alveolitis (EAA) are clinical entities of growing importance. The discovered etiological agents which can induce them, organic and inorganic substances of low molecular weight which are frequently found in the laboral environment, are every day more numerous. In the group of substances which are rarely implied in EAA etiology, we must mention esparto (Stipa tenacissima), a grass of the graminea family widely used in Spain. The EAA caused by Stipa tenacissima inhalation in known as stipatosis, a disease with poorly systematized clinical manifestations because of the few cases described in the literature so far. Our purpose in this report is to show the second case, in world literature, of EAA correctly characterized.