A new section at Jebel Gorraa, in northern Tunisia, contains the Paleocene–Eocene transition interval. Sample analysis of the section delivers abundant and diverse microfauna of planktonic and benthic foraminifera. Biostratigraphically, the Acarinina sibaiyaensis index-species is identified for the first time in this region, which allows us to specify the location of the Paleocene–Eocene boundary as well as the first E1 biozone of the lower Eocene. Samples from this biozone contain calcitic tests poorly preserved with an enrichment of iron oxide signifying a period of upheaval in local marine environments linked to the global warming of the Paleocene–Eocene Thermal Maximum (PETM), the marker for the P/E boundary.