The study of macrobotanical remains recovered from excavations at Otumba provides evidence for past vegetation and the plants used by inhabitants of different sectors of the archaeological site. Opportunistic weedy genera commonly associated with crops were common among the archaeological specimens. Evidence for domesticated plants includes maize (Zea mays) and frijol (Phaseolus sp.), together with numerous genera that do not appear to have been domesticated as yet, such as Amaranthus sp., Chenopodium sp., Portulaca sp., and Salvia sp. The relative abundance of uncarbonized plant specimens in association with carbonized materials is discussed. The possibility of differential plant use among inhabitants of the nucleated core with respect to the dispersed residential zone is also considered.