Although their existence in sedimentary rocks is rarely referred to in previous studies, fossil didemnid ascidian spicules were encountered in the rock samples of the Late Pliocene-Early Pleistocene marine clastics located in the Antalya Basin (Southern Turkey). Some ascidian spicules were identified in investigations of mudstone and sandstone rock samples from the Geceleme and Karpuzcay formations, from outcroppings around the Manavgat-Oymapinar and Antalya-Akseki Roads. These samples represent a clastic sedimentation belonging to a coastal or shelf area, and identified spicules include Monniotia cf. fasciculata, Micrascidites vulgaris Deflandre & Deflandre-Rigaud, Bonetia brevis Varol & Houghton, Bonetia truncata Varol & Houghton, and Rigaudia multiradiata Varol & Houghton. With the inclusion of abundant evidence of reworking of Early Pliocene, Early Miocene, Early-Mid Eocene, and Late Cretaceous deposits, nannofossil assemblages of these rock samples are probably indexed to the NN15-NN19 nannofossil zones. According to newly identified nannofossil data, it is concluded that these spicules were remnants of the Late Pliocene didemnids living on the southwest Anatolian shelf of the Eastern Mediterranean.