An ethnobotanical inventory of lianas was carried out in a 1-ha plot of tropical moistforest in the Cuyabeno Reserve, Amazonian Ecuador. We obtained information about the uses that the Siona-Secoya Indians have for lianas. Of 980 species in the 1-ha plot, 479 were useful for the Siona-Secoya. Of the species used, 679 were for medicines, food, stimulants, and poisons; 179 had ritual applications, and 15% were used to make ropes or to weave baskets, toys, and ornaments. The species of lianas that were most useful were the ones with the highest values of ecological parameters such as density, dominance, and relative length. There is a close relationship between the ecological characteristics of the liana community and the uses made of it by the Indians.