Burkard volumetric samplers were used to carry out research on airborne pollen in the Ascoli Piceno and Siena atmosphere in the period April-September 1981. Total production in the period in question was quantitatively similar, with a prevalence of non-arboreal pollen in both stations. The overall trend has shown a positive correlation between the two stations. Differences were recorded with regard to the period of pollination and the quantity of pollen produced byQuercus, Poaceae, Oleaceae,Castanea, Plantaginaceae and Compositae.