This work focuses on the sedimentation and geomorphology of the Messenia and Eastern Lakonia Peninsulae (S Peloponnese, Greece) during the Pliocene-Quaternary (last ca. 5 Ma). Shallow-marine and subaerial sediments and landforms are described and interpreted in terms of tectonic and sea level controls. The S Peloponnese underwent regional uplift since the Middle Miocene. Normal faulting, in directions parallel and transverse to the Aegean Arc led to the formation of horsts and grabens on scales varying from <1 to >20 km. Sea level cyclicity resulted in deposition of shallow-marine to subaerial sequences separated by unconformities. Changing climatic conditions since the Middle-Late Miocene influenced subaerial erosion and sedimentation and also the facies/fauna of marine and marginal marine deposits. Pliocene-Quatemary landforms and sediments in the two areas studied reflect the interplay between the above controls. In both the Ntessenia and Eastern Lakonia Pensinsulae Late Tertiary surfaces of subaerial erosion and Quaternary marine sediments and terraces are present at progressively lower altitudes with decreasing age as a result of uplift and forced regression. Maximum numbers of terraces are present in fault-bounded areas of maximum Quaternary uplift, in the NW parts of each peninsula, where uplift rate since the early Pleistocene (last ca. l Ma) was 0.08-0.35 m/ka. Pliocene (only in the Messenia Peninsula) and Quaternary shallow-marine sediments (in both peninsulae) are subdivided into informal units, correlated with 3^rd or higher-order sea level cycles. The Pleistocene part of the stratigraphy, present in both peninsulae, is resolved into two 3^rd order sequences, of early and middle-late Pleistocene age, respectively. The middle-late Pleistocene sequence is further divided into Eutyrrhenian and Neotyrrhenian units, correlated with higher order late Pleistocene sea level cycles.