The nematode Radopholus similis is a major pest in banana plantations worldwide. This nematode is actually controlled using synthetic, toxic nematicides. Alternative control methods are therefore needed. For instance the liquid byproduct of fiber extraction from sisal (Agave sisalana) may be used as a nematicide. Here we tested the nematicidal activity of the sisal residue, fresh or fermented, on R. similis in banana plants. We measured immobility and mortality effects by nematode immersion in an aqueous solution of sisal residue for 24 and 48 h. Nematode control was also evaluated in the Grand Naine banana plants under greenhouse conditions using soil amendments of residues. We measured plant growth, pseudostem diameter, the number of leaves, and the dry weight of the aerial parts, corm and roots, aswell as factors related to nematode control such as the level of damage, the population of R. similis in roots and soil, and nematode reproduction factors. Our results show that the sisal residue efficiently controlled R. similis in vitro, displaying mortality rates of 99.2 % for the fresh residue. The damage caused by R. similis on plants was similar for the treatment with the sisal residue at a concentration of 25 % and with the nematicide. This is the first report on the nematicidal effect of the sisal liquid residue on the banana burrowing nematode. This byproduct presents the potential for the development of new alternatives for nematode control, with a low-cost and lowenvironmental risk plant nematicide. ; The authors wish to thank the National Council for Research (CNPq), Foundation for Research of the State of Bahia (FAPESB), and Foundation for Qualification of People for Superior Education (CAPES) for funding this research and providing scholarships.