The dataset relates to the AZ16 section of the Eocene Peshtasar volcanic succession in the Talysh Mountains, southeastern Azerbaijan. It contains data from 25 volcanic cooling units divided into three stratigraphically organised paleomagnetic directional groups. The deposited files include specimen-level paleointensity experimental data, paleomagnetic directional data, rock-magnetic measurements, methodological information and file-level metadata. Paleointensity estimates were obtained using thermal Thellier, microwave, pseudo-Thellier, double-heating Shaw and Triaxe methods. The resulting dataset was used to test whether the three directional groups record systematic differences in geomagnetic field strength. The accepted results show moderate-to-strong fields for Groups 1 and 2 and a substantially weaker field for Group 3, providing evidence for coupled directional and intensity changes during Eocene geomagnetic secular variation. The data relate to the AZ16 volcanic section of the Eocene Peshtasar Formation in the Talysh Mountains of southeastern Azerbaijan, close to the western margin of the South Caspian Basin. Sampling sites AZ16A-Z extend through the Peshtasar volcanic succession west and southwest of Yardimli. Data supports the manuscript 'Extreme Eocene secular variation revealed by coupled paleomagnetic directional and paleointensity changes in the Talysh volcanic succession'