The Taleh Zang Formation is a carbonate sequence of the late Paleocene–early Eocene age in the Lorestan zone, west of Iran. This Formation overlays siliciclastic rocks of the Amiran Formation and is overlain by red sandstone of the Kashkan Formation. A biostratigraphic scheme, based on the larger benthic foraminifera, is proposed for the Thanetian–Ilerdian deposits in Lorestan Zone. We compare our results with the available data from other parts of Tethys and the zonation of shallow-marine Paleocene–Eocene of Mediterranean Tethys is made. In total, 367 samples were collected from the six sections. From a biochronostratigraphic point of view, three biozones and one indeterminate zone are identified. The zones are shallow benthic zone 3 (early Thanetian), shallow benthic zone 4 (late Thanetian), and shallow benthic zone 6 (early Ilerdian). In the northern part of the Lorestan Zone (Kabutar Bula and Psht-e Jangal sections), the Taleh Zang Formation contains poor fauna. Due to the stratigraphic position, an early Thanetian age can be considered. Our data showed that the late Paleocene and Eocene biozones in Lorestan Zone developed parallel to the axis of the folding, in a northwest-southeast trend. They get younger from the northeast to the southwest. Keywords: biostratigraphy, Eocene, Foraminifera, Lorestan Zone, Paleocene.