Ten cotton, Gossypium hirsutum L., cultivars or breeding-lines were evaluated for relative susceptibility to charcoal rot, which is caused by Macrophomina phaseolina (Tassi) Goidanich. The cultivars were Texas 121, AP 4103, AP 6101, and Stoneville 474 and experimental seed-lines were NK 2165C, NK 21208SS, NK 2387C, NKX C429-93-2ct, NKX 2907, and NKX 2207. By 21 July, cotton plants were wilting and dying. Macrophomina phaseolina was identified by the presence of the sclerotia on the roots of affected plants. On 3 September, the disease incidence was evaluated within in 13-foot section of each of two rows within each plot. Charcoal rot disease incidence was highest in NKX C429-93-2ct. Disease incidence was lowest in AP 6101and Stoneville 474, which did not differ from AP 4013, NKX 2207, NK 2387C.