The primary aim of this study was to investigate a range of strategies for the identification of molecular markers linked with Verticillium wilt response in cotton. The research was carried out on the parental G. hirsutwn cultivars Sicala V-1 (wilt-tolerant) and Siokra 1-4 (wilt-susceptible) together with progeny derived by crossing these plants. A new disease grading system based on foliar symptoms, vascular discolouration and plant stunting was developed in order to compare plant responses to Verticillium wilt disease following pathogen inoculation. A study of inheritance showed for the first time that a single genetic locus, designated VwRJ, was responsible for tolerance to Verticillium wilt in Sicala V-1.