The occurrence of dinoflagellate cysts in Neogene and Holocene sediments from the Southern Ocean is now becoming reasonably well documented. For some years it was thought that there were no post-Paleogene dinoflagellate cysts within Southern Ocean sediments (McMinn, 1995) because the geographical and thermal isolation of Antarctica had effectively prevented the migration of the dinoflagellates that produce hypnozygotic cysts. Recent research (Marret and de Vernal, 1997; Harland et al., 1998, 1999; Harland and Pudsey, 1999), however, has established the occurrence of dinoflagellate cysts, which were found in sediment traps and Quaternary sediments, within the waters of the Southern Ocean. In addition, Wrenn et al. have reported dinoflagellate cysts from the lower Miocene and Quaternary of East Antarctica by Wrenn et al. (1999). Our contribution aims to add to the knowledge of Southern Ocean Neogene dinoflagellate cysts by describing assemblages from the Miocene and Pliocene of the Antarctic Peninsula margin, recovered during Ocean Drilling Program (ODP) Leg 178, Sites 1095 and 1096.