The Hocakoy section, measured in the Alakircay Nappe of Antalya Nappes in SW Turkey, is one of the key sections that contains Upper Triassic to Middle Cretaceous Radiolaria bearing pelagic sediments. The lower part of the section is the Upper Triassic Gokdere Formation (cherty-limestone/limestone-chert alternation), while the upper part is the Jurassic-Cretaceous Hocakoy Radiolarite (mainly chert-mudstone alternation with some limestone interlayers). Thin bedded limestone beds at base of the Hocakoy Radiolarite contain moderately to well-preserved middle Hettangian-lower upper Sinemurian radiolarians. Radiolaria obtained from these basal limestone beds resemble and are correlative to the fauna from Queen Charlotte Island, British Columbia by Carter et al. (1998). Pantanellium browni (middle-upper Hettangian), Crucella hettangica (uppermost Hettangian-lowermost Sinemurian), Parahsuum simplum (lower Sinemurian) and Canutus rockfishensis-Wrangellium thurstonense (lower upper Sinemurian) radiolarian zones are recognized in this part of the section. In this study, 61 species and 14 taxa belonging to open nomenclature are investigated and 4 species are described as new, namely Bistarkum equalum, Praehexasaturnalis merici, Katroma hocakoeyensis and K. sashidai.