A rich and diverse assemblage of large benthic foraminifera from the Eocene carbonates in the south Sabzevar region (Cheshmeh Hadi section) of central Iran suggests an age range from early Lutetian to early Bartonian. The assemblage includes six species of nummulitids: Assilina placentula (Deshayes) ex. interc. A. cuvillieri Schaub, A. aff. laxispira, Nummulites preadiscorbinus Schaub, N. obesus d'Archiac and Haime, N. deshayesi D’Archiac and Haime and N. perforatus De Montfort, along with Alveolina ozcani Hadi and Consorti and A. kieli Sirel and Acar. Detailed analysis identifies these taxa as indicative of shallow benthic zones (SBZs) 12 to 17, spanning from the early Lutetian to the early Bartonian. The age model is based on both SBZ and calcareous nannofossil (CN) biostratigraphy, with the latter corresponding to the NP15 biozone and possibly the lower part of the NP16 biozone, as recorded in the central portion of the studied section. This combined approach enhances the robustness of the age model, providing a consistent framework for the correlation of SBZ and CN biozones.