Karakaya Complex in northern Turkey is a tectonic assemblage of strongly deformed Permo-Triassic mafic volcanic and clastic rocks, representing subduction-accretion complexes of the Paleo-Tethys. It forms an over 1000 km long discontinuous east-west trending belt and constitutes the basement to the little deformed Jurassic-Cretaceous sequence of the Pontides. In northwest Turkey four tectonic units are differentiated within the Karakaya Complex. A basal metabasite-marble-phyllite sequence, an arkosic sandstone-olisto-Strome unit, a greywacke unit and a mafic lava-tuff-olistostrome unit. The latter three units comprise numerous exotic blocks of Permo-Carboniferous limestone ranging up to one kilometre in size. Forami-nifera from over 180 blocks from these three Karakaya Complex units are studied, many in oriented sections. The rich fusulinid and small foraminifer assemblage in the blocks of the Karakaya Complex with three new fusulinid species, Triticites (?) kozakensis, Palaeofusulina (Paradunbarula) okayi and Palaeofusulina (Paradunbarula) ottomana, indicate the presence of all the Carboniferous and Permian stages with the exception of Tournaisian, Kasimovian and Bolorian. However, the majority of the limestone blocks (> 80%) are of Murgabian to Midian age. Compared to the Upper Paleozoic sequences from the Anatolide-Taurides, the limestone blocks in the Karakaya Complex are characterised by richer fusulinid assemblages and a more complete synthetic sequence suggesting that they were deposited to the north of the Anatolide-Tauride platform along the southern or northern margin of the Paleo-Tethys. The concentration of the olistostromes along the suture with the Anatolide-Taurides suggests that the limestone blocks were derived from the southern margin of the Paleo-Tethys. However, fusulinid assemblages of the Karakaya Complex show similarities to those from Urals, northern Pamir and Darvaz, all thought to be located along the northern margin of the Paleo-Tethys, suggesting an opposing view. This could be due to the narrow width of the Permian Paleo-Tethys in the Turkish paleo-longitude, which might have obliterated faunal differences in fusulinid assemblages from both sides of the ocean.