Abstract: A moderately diverse larger foraminiferal fauna from the north‐east Italian ‘Arenarie e calcari di S. Urbano’ formation with important stratigraphic, palaeoecological and palaeobiogeographical implications is described with respect to its position in the Western Tethys area. The fauna is dominated by hyaline perforated and porcellaneous forms includingAmphistegina,Archaias,Austrotrillina,Miogypsinoides,Neoplanorbulinella,Neorotalia,Nummulites,OperculinaandSpiroclypeus.The presence ofMiogypsinoides complanatusallows the age of the formation to be determined as late Chattian (Shallow Benthic Zone SBZ 23). The palaeoenvironmental setting is interpreted as a shallow ramp environment ranging from (1) well lit, highly translucent, shallowest part of the photic zone characterized byArchaiasandAustrotrillina, the deeper part of the inner ramp withNummulites, to (2) the shallow part of the middle ramp withSpiroclypeusand miogypsinids andOperculina, to (3) a deeper middle‐ramp setting dominated by coralline rhodoliths along with lepidocylinids. The presence ofArchaias hensoniSmout and Eames shows that members of much more diverse Middle Eastern associations of shallow‐water larger porcellaneous foraminifera are also present in the north‐western parts of the Western Tethys, and reveals a corresponding diversity gradient among larger foraminiferal faunas in the Western Tethys, which is related to a decrease in temperature.