Abstract: This study was carried out to determine the influence of limited irrigation on growth; seed yield and yield components, and water use and water efficiency of sunflower under Thrace conditions. Five irrigation treatments were applied, designated as T1 full irrigation, and T2, T3, T4 and T5 received 75, 50, 25 and 0 % of applications of the fully irrigated treatment on the same day. Seed yields averaged highest with full irrigation treatment (T1) and differences between full irrigation and other treatments were significant. Although linear relationships were found between seed yield versus total irrigation water, and seed yield versus seasonal evapotranspiration, respectively. The yield response factor (ky) was determined as 0.98, 0.77 and 0.69 (avg 0.78) during the experimental years. Irrigation water use efficiency (IWUE) and water use efficiency (WUE) were found to be between 0.80 – 2.47 kg/da-mm and 0.62 – 0.94 kg/da-mm, respectively, for the treatments.