A contribution to the fossil Silicoflagellates of the late Miocene in Central Italy. - A microscopic analysis of fourteen diatomite samples from a Messinian (late Miocene) stratigraphic series, in central-eastern Italy, has been carried out in order to verify the presence of Silicoflagellates. The skeletons of eight taxa were found in good condition and identified. The most abundant and continuous in the stratigraphic series examined areDictyocha fibulaandDistephanus speculum, also known in the present-day seas;Cannopilus sphaericus, a very rare and interesting species extinct in the Miocene, is limited to only two samples. On the basis of the Silicoflagellates found, it is possible to suggest that they lived in an open sea with 30–40‰ salinity and a temperature of 10–20°C. A very similar situation is present nowadays in the middle-western Adriatic Sea.