Because of their durability and widespread use, ceramics in the Pacific are important artifacts for examining patterns of prehistoric subsistence, settlement, and societal interaction. Numerous studies demonstrate that petrographic analysis of prehistoric pottery in western Oceania can differentiate temper sands and other mineral constituents unique to geotectonically different islands. However, a detailed study of tempering agents has not been attempted for ceramic assemblages in Palau, Western Caroline Islands, Micronesia. We present the first major synthesis of Palauan ceramic petrography and petrological classification. The analysis of several sherd suites recovered from both the volcanic and limestone islands in the archipelago and other nearby western Micronesian atolls suggest that pottery was locally made, manufactured using primarily grog or composite (mixed-grog sand) tempers, and transported to smaller islands within and outside of the Palauan archipelago. The research has implications for determining raw material acquisition by ancient Palauan potters and is a critical step for developing regional models of intra- and inter-island exchange and interaction.