This paper presents the results of plant macro-remain and phytolith analyses from two Neolithic-Early Historic mounded settlement sites in Odisha, eastern India: Gopalpur and Golbai Sasan. Macrobotanical and phytolith samples were taken throughout the stratigraphy and the results are presented here. The plant remains confirm the presence of a distinct agricultural economy in Neolithic-Chalcolithic Odisha based on rice (Oryza sativa), pulses (Vigna spp., Macrotyloma uniflorium and Cajanus cajan) and millets (Bracharia ramosa, Panicum spp., Setaria spp. and possibly Paspalum sp.). Crop processing activities have been reconstructed using both phytoliths and macro-remains, and suggest that threshing occurred off site as part of a communal harvesting strategy. Potential differences between the economies of Golbai Sasan and Gopalpur are suggested, with a broader range of pulses present at Gopalpur. Radiocarbon dates from individual rice grains and legumes provide a secure chronology for the sites. This paper therefore provides the first published details for the agricultural base of the Neolithic-Chalcolithic coastal lowlands in Odisha, as well as new AMS radiocarbon dates for the Odishan Neolithic-Chalcolithic period.