Water stress is one of the main factors that contribute to the retardation of growth of cotton plants infected by Verticillium dahliae, especially during the early stages of disease development (2). The purpose of this study was to investigate the influence of different pathotypes of V. dahliae on the host responses that are associated with water stress. Both greenhouse and field-grown cotton plants (Gossypium hirsutum cv. Acala SJ-2) were stem-puncture inoculated with conidial suspensions of T9 (defoliating) and SS4 (non-defoli ating) pathotypes of V. dahliae. Control plants were injected with distilled water.