Papaya (Carica papaya L.) seeds were used as adsorbent to remove amaranth dye from synthetic wastewaters. The effects of pH, initial dye concentration and contact time were investigated. The equilibrium data were analyzed by Langmuir, Freundlich and Temkin isotherm models. Adsorption kinetic data were fitted with the pseudo-first order, pseudo second-order and Elovich models. It was found that the Langmuir model was the most suitable to represent the adsorption process, being the maximum adsorption capacity of 37.4 mg g-1. A fast kinetic was observed and the data followed the pseudo second-order model. In summary, these results demonstrated that the papaya seeds are a low cost and alternative adsorbent to remove amaranth dye from aqueous solutions.