ABSTRACT: The Paleocene-Eocene transition is exposed at Gebel Serai, 50km east of Qena, and at Taramsa, 10km west of Qena in the central Nile Valley of Egypt. The continuous deposition across the P/E boundary, the negative d13C excursion (CIE), the good preservation and high diversity of the calcareous nannofossil assemblages as well as the occurrence of distinctive floral events confer to these localities a potential role as P/E reference-sections. A major nannofossil turnover occurs around the P/E boundary (NP9a/NP9b subzonal boundary)marked by an abrupt decrease of Fasciculithus spp. at the onset of CIE concomitant with a sharp decrease in the abundance of Toweius spp.. The middle and upper part of the CIE-interval are characterized by successive shifts of oligotrophic, warm-water taxa, including the first acme of Coccolithus pelagicus/subpertusa, followed by a rapid increase in abundance of Rhomboaster spp., a sharp increase of long-armed, asymmetrical discoasters, and a second shift of Coccolithus pelagicus/subpertusa. Immediately above the CIE-interval and continuing up to the top of the section, a gradual increase of Toweius spp. accompanied by a gradual decrease in Coccolithus pelagicus/subpertusa indicates a return to a cooler, mesotrophic to eutrophic environment.