[EN] Tomato yellow leaf curl disease (TYLCD) produces significant production losses in tomato crops (Solanum lycopersicum L.) in all warm and temperate regions of the world. The most important viral species that causes the disease is the Tomato yellow leaf curl virus (TYLCV). Resistant materials have been developed to date with high levels of resistance. S. chilense has been cited as the specie with higher levels of the resistance to this disease. Specifically, most of the commercially available resistant materials incorporate the Ty-1 gene, derived from LA 1969 accession of this species. In any case, the available commercial materials are not a definitive solution, because they show symptoms under high inoculum pressure or upon early infections. Thus many research groups are working in the search for resistance sources. Resistance has been described in other accessions of S. chilense such as LA1932, LA1960 and LA1971. In the Instituto Universitario de Conservación y Mejora de la Agrodiversidad Valenciana lines fixed for resistance derived from these accessions are available, as well as segregating generations derived from these lines. This work forms part of a project that aims to identify the loci responsible of the resistance derived from these accessions and to fine map them. Specifically, the objectives of this study were the following. The first purpose was to identify polymorphic molecular markers between tomato and S. chilense accessions used, to subsequently use these markers for the localization of the introgressed regions of S. chilense in fixed resistant lines. Finally, the objective was to analyze the association between the identified introgressions of S. chilense and TYLCD resistance detected in the segregating generations available. The 18 microsatellites markers analyzed were polymorphic between tomato and S. chilense. These markers and two CAPS markers (Cleaved Amplified Polymorphic Sequence), previously described as polymorphic between both species and linked to the Ty-1 gene on chromosome 6 were used for the genotyping. Only the introgression for the chromosome 6 was common to all five lines evaluated. In any case, all the markers for which the F1 generations derived from the cross between the lines and the tomato variety Fortuna C were heterozygous, were used for genotyping of the F2 generation, previously phenotyped for its resistance to TYLCD. Association was only observed between the resistance and the presence of S. chilense allele for the markers of chromosome 6. In previous works the presence of the resistant Ty-3 gene derived from LA1932 on chromosome 6 was described. However, it is the first study in which the resistance loci from LA1971 and LA1960 are mapped. Future works will be aimed at the identification of markers most tightly linked to the resistance genes, in order to verify if the loci derived from LA1932, LA1960 and LA1971 are allelic with the previously described Ty-1 and Ty-3 genes on chromosome 6.