In the Klematia-Paramythia Basin, which belongs to the middle Ionian zone and is part of the Pindos Foreland Basin, submarine fan deposits accumulated from the Middle Eocene to the Middle Miocene. Calcareous nannofossils are used as a tool for dating and correlation of the fan sediments. Calcareous nannofossil assemblages have been studied in four main geological cross-sections, located in the Pindos Foreland Basin. Seven nannofossil biostratigraphic units were detected — two in the Middle and Upper Eocene (NP16, NP17–20), one in the Lower Oligocene (NP21), one in the Upper Oligocene (NP24–25), two in the Lower Miocene (NN1, NN2–3) and one in the Middle Miocene (NN7). The Upper Miocene NN8–12 interval probably occurs in the section A–A’. These age data indicate that the Pindos foredeep, as a result of Pindos thrust activity, began subsiding during the Middle Eocene. The basin was filled by submarine fan deposits until the Middle (Late?) Miocene, when internal thrusting ended sedimentation.