Cotton (Gossypium spp.) is attacked by parasitic nematodes including the reniform nematode (Rotylenchulus reniformis Linford and Oliveira). Options for management of reniform nematode are limited. No cultivars of upland cotton (G. hirsutum L.) have genetic resistance. Genetic resistance is an environmentally safe method of pest management. The primary limitation to developing cotton germplasm with resistance to RN is the paucity of information available about resistance gene(s). Molecular markers linked to RN-resistance gene(s) would provide the option to select by genotype rather than by phenotype. An accurate and detailed map of the RN gene(s) associated with DNA markers will be a valuable tool to expedite the breeding process by identifying resistant lines. A DNA marker linked closely to a gene of interest might also provide a tool for positional cloning of the gene of interest. The objectives of this research are 1) to identify DNA markers associated with the resistance to reniform nematodes in upland cotton, and 2) to determine the mode of inheritance of the reniform nematode resistance gene(s). Our work is to cross the moderately resistant lines, TEX 1419, TEX 1565 and TEX 1765 with the susceptible cultivar, TM-1 and also to screen for resistance and to genotype using simple sequence repeat (SSR) primer pairs from different series (BNL, MUCS and MUSS) the resulting F₁ and F₂ populations and both parents.